[Metal] `Feature/HLSLLib/firstbithigh.16.test` fails on Metal

Nobody has claimed this yet.

The test `Feature/HLSLLib/firstbithigh.16.test` fails on Metal because the no bit set terminal is returned as 4294901776 instead of 4294967295 on both Clang and DXC.

Note: Previously there would be a 'gpu-exec: error: Failed to materializeAll.:' when running with Clang, but that appears to no longer be the case.

Logs (DXC): https://github.com/llvm/offload-test-suite/actions/runs/19942216828/job/57182673462?pr=590#step:12:225
```
FAIL: OffloadTest-mtl :: Feature/HLSLLib/firstbithigh.16.test (114 of 297)
******************** TEST 'OffloadTest-mtl :: Feature/HLSLLib/firstbithigh.16.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Using Metal API
Created compute commands.

--
Command Output (stderr):
--
/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/split-file /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/OffloadTest/test/Feature/HLSLLib/firstbithigh.16.test /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp # RUN: at line 94
+ /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/split-file /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/OffloadTest/test/Feature/HLSLLib/firstbithigh.16.test /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp
"/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/DXC/build/bin/dxc-3.7" -metal -T cs_6_5 -enable-16bit-types -Fo /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/source.hlsl # RUN: at line 95
+ /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/DXC/build/bin/dxc-3.7 -metal -T cs_6_5 -enable-16bit-types -Fo /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/source.hlsl
/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/offloader -debug-layer /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/pipeline.yaml /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o # RUN: at line 96
+ /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/offloader -debug-layer /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/pipeline.yaml /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o
2025-12-04 14:40:50.246 offloader[84725:575877771] *** -[NSAutoreleasePool addObject:]: Do not use this instance method on specific pools -- just use -autorelease instead.
Test failed: Test1
Comparison Rule: BufferExact
Expected:
---
Name: ExpectedOut
Format: UInt32
Stride: 16
Data: [ 4294967295, 3, 0, 15, 4294967295, 3, 0, 15, 4294967295,
2, 3, 4294967295 ]
OutputProps:
Height: 0
Width: 0
Depth: 0
...
Got:
---
Name: Out
Format: UInt32
Stride: 16
Data: [ 4294901776, 3, 0, 15, 4294901776, 3, 0, 15, 4294901776,
2, 3, 4294901776 ]
OutputProps:
Height: 0
Width: 0
Depth: 0
...
Full Hex 64bit representation of Expected Buffer Values:
[ 0xffffffff, 0x3, 0x0, 0xf, 0xffffffff, 0x3, 0x0, 0xf, 0xffffffff, 0x2, 0x3, 0xffffffff ]
Full Hex 64bit representation of Actual Buffer Values:
[ 0xffff0010, 0x3, 0x0, 0xf, 0xffff0010, 0x3, 0x0, 0xf, 0xffff0010, 0x2, 0x3, 0xffff0010 ]
```

Logs (Clang): https://github.com/llvm/offload-test-suite/actions/runs/19942216828/job/57182673499?pr=590#step:12:696
```
FAIL: OffloadTest-clang-mtl :: Feature/HLSLLib/firstbithigh.16.test (115 of 297)
******************** TEST 'OffloadTest-clang-mtl :: Feature/HLSLLib/firstbithigh.16.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Signed DxilContainer written to "/var/folders/zv/v734td6n3_3fl4qmc2hcdkcc0000gn/T/lit-tmp-w3sv9il9/source-c77a20.dxo"
Validation succeeded.Using Metal API
Created compute commands.

--
Command Output (stderr):
--
/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/split-file /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/OffloadTest/test/Feature/HLSLLib/firstbithigh.16.test /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp # RUN: at line 94
+ /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/split-file /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/OffloadTest/test/Feature/HLSLLib/firstbithigh.16.test /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp
/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/clang-dxc -metal --dxv-path=/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/DXC/build/bin -T cs_6_5 -enable-16bit-types -Fo /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/source.hlsl # RUN: at line 95
+ /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/clang-dxc -metal --dxv-path=/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/DXC/build/bin -T cs_6_5 -enable-16bit-types -Fo /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/source.hlsl
/Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/offloader -debug-layer /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/pipeline.yaml /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o # RUN: at line 96
+ /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/bin/offloader -debug-layer /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp/pipeline.yaml /Users/cbieneman/actions-runner/_work/offload-test-suite/offload-test-suite/llvm-project/build/tools/OffloadTest/test/clang-mtl/Feature/HLSLLib/Output/firstbithigh.16.test.tmp.o
2025-12-04 14:46:52.638 offloader[11775:575941250] *** -[NSAutoreleasePool addObject:]: Do not use this instance method on specific pools -- just use -autorelease instead.
Test failed: Test1
Comparison Rule: BufferExact
Expected:
---
Name: ExpectedOut
Format: UInt32
Stride: 16
Data: [ 4294967295, 3, 0, 15, 4294967295, 3, 0, 15, 4294967295,
2, 3, 4294967295 ]
OutputProps:
Height: 0
Width: 0
Depth: 0
...
Got:
---
Name: Out
Format: UInt32
Stride: 16
Data: [ 4294901776, 3, 0, 15, 4294901776, 3, 0, 15, 4294901776,
2, 3, 4294901776 ]
OutputProps:
Height: 0
Width: 0
Depth: 0
...
Full Hex 64bit representation of Expected Buffer Values:
[ 0xffffffff, 0x3, 0x0, 0xf, 0xffffffff, 0x3, 0x0, 0xf, 0xffffffff, 0x2, 0x3, 0xffffffff ]
Full Hex 64bit representation of Actual Buffer Values:
[ 0xffff0010, 0x3, 0x0, 0xf, 0xffff0010, 0x3, 0x0, 0xf, 0xffff0010, 0x2, 0x3, 0xffff0010 ]
```

Start with OffloadTest/test/Feature/HLSLLib/firstbithigh.16.test and reproduce the Metal runs for both DXC and Clang. Compare the expected 0xffffffff values with the observed 0xffff0010 values; the work is done when the test passes on both Metal configurations.

Written by the indexing model from the issue text.