[spirv-val] OpCooperativeMatrixLoadKHR not checking if loading through an array

The spec says

but found that if I remove the array, there is no validation error

@jeffbolznv so what is the exact restriction here? I notice a basic glslang shader will "loads through" the array as its in the middle of the access chain, but what was the real thing you are trying to avoid? something around variable pointer?

```
%5 = OpTypeRuntimeArray %9
%6 = OpTypeStruct %5
%15 = OpTypePointer StorageBuffer %6
%4 = OpVariable %15 StorageBuffer

%24 = OpAccessChain %19 %4 0 0
%25 = OpCooperativeMatrixLoadKHR %13 %24 ...
```

----

```
TEST_F(ValidateMemory, CoopMatMatrixLoadNonArray) {
const std::string body =
R"(
OpCapability Shader
OpCapability VulkanMemoryModel
OpCapability CooperativeMatrixKHR
OpExtension "SPV_KHR_cooperative_matrix"
OpMemoryModel Logical Vulkan
OpEntryPoint GLCompute %main "main" %matA %inputA
OpExecutionMode %main LocalSize 16 1 1
OpDecorate %_arr_uint_uint_1 ArrayStride 4
OpDecorate %InputA Block
OpMemberDecorate %InputA 0 Offset 0
OpDecorate %inputA Binding 0
OpDecorate %inputA DescriptorSet 0
%void = OpTypeVoid
%4 = OpTypeFunction %void
%uint = OpTypeInt 32 0
%uint_3 = OpConstant %uint 3
%uint_16 = OpConstant %uint 16
%uint_0 = OpConstant %uint 0
%11 = OpTypeCooperativeMatrixKHR %uint %uint_3 %uint_16 %uint_16 %uint_0
%_ptr_Private_11 = OpTypePointer Private %11
%matA = OpVariable %_ptr_Private_11 Private
%uint_1 = OpConstant %uint 1
%_arr_uint_uint_1 = OpTypeArray %uint %uint_1
%InputA = OpTypeStruct %uint
%_ptr_StorageBuffer_InputA = OpTypePointer StorageBuffer %InputA
%inputA = OpVariable %_ptr_StorageBuffer_InputA StorageBuffer
%int = OpTypeInt 32 1
%int_0 = OpConstant %int 0
%uint_5 = OpConstant %uint 5
%_ptr_StorageBuffer_uint = OpTypePointer StorageBuffer %_arr_uint_uint_1
%v3uint = OpTypeVector %uint 3
%26 = OpConstantComposite %v3uint %uint_16 %uint_1 %uint_1
%main = OpFunction %void None %4
%6 = OpLabel
%23 = OpAccessChain %_ptr_StorageBuffer_uint %inputA %int_0
%24 = OpCooperativeMatrixLoadKHR %11 %23 %int_0 %uint_16 MakePointerVisible|NonPrivatePointer %uint_5
OpStore %matA %24
OpReturn
OpFunctionEnd
)";

CompileSuccessfully(body.c_str(), SPV_ENV_VULKAN_1_3);
ASSERT_EQ(SPV_ERROR_INVALID_DATA, ValidateInstructions(SPV_ENV_VULKAN_1_3));
EXPECT_THAT(getDiagnosticString(), HasSubstr("TODO"));
}
```