[RISCV] Assertion `LVI->end >= Stop && "range ends mid block with no uses"' failed.

Reproducer: https://godbolt.org/z/jdxW8hnY8
Testcase:
```llvm
target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
target triple = "riscv64-unknown-linux-musl"

define i32 @func_1(i16 %conv, i1 %tobool.not) #0 {
entry:
br label %BS_LABEL_9

BS_LABEL_9: ; preds = %BS_LABEL_1, %entry
%0 = insertelement <16 x i16> zeroinitializer, i16 %conv, i64 0
br label %for.body

for.body: ; preds = %for.body, %BS_LABEL_9
%l_4157.093 = phi i32 [ 1, %BS_LABEL_9 ], [ 0, %for.body ]
%call = tail call i64 null()
br i1 %tobool.not, label %for.end21.loopexit, label %for.body

for.end21.loopexit: ; preds = %for.body
%conv1.le = trunc i32 %l_4157.093 to i16
%vecinit16.le = insertelement <16 x i16> %0, i16 %conv1.le, i64 1
br label %BS_LABEL_12.outer

BS_LABEL_12.outer: ; preds = %BS_LABEL_1, %for.end21.loopexit
%BS_VAR_4.4.ph135 = phi <16 x i16> [ %vecinit16.le, %for.end21.loopexit ], [ %BS_VAR_4.4, %BS_LABEL_1 ]
br label %BS_LABEL_12

BS_LABEL_12: ; preds = %cleanup63, %BS_LABEL_12.outer
%BS_VAR_4.4 = phi <16 x i16> [ %BS_VAR_4.4.ph135, %BS_LABEL_12.outer ], [ %BS_VAR_4.5, %cleanup63 ]
br label %for.cond42

for.cond42: ; preds = %cleanup63, %BS_LABEL_12
%BS_VAR_4.5 = phi <16 x i16> [ %BS_VAR_4.4.ph135, %BS_LABEL_12 ], [ zeroinitializer, %cleanup63 ]
br label %BS_LABEL_1

cleanup63: ; preds = %BS_LABEL_1
switch i32 0, label %cleanup63.unreachabledefault116 [
i32 0, label %for.cond42
i32 13, label %BS_LABEL_12
i32 23, label %BS_LABEL_1
]

BS_LABEL_1: ; preds = %BS_LABEL_1, %cleanup63, %for.cond42
callbr void asm sideeffect "", "!i,!i,!i,!i"()
to label %cleanup68 [label %BS_LABEL_12.outer, label %BS_LABEL_1, label %cleanup63, label %BS_LABEL_9]

cleanup63.unreachabledefault116: ; preds = %cleanup63
unreachable

cleanup68: ; preds = %BS_LABEL_1
ret i32 0
}

attributes #0 = { "target-features"="+v" }
```

Dump:
```
llc: /root/llvm-project/llvm/lib/CodeGen/SplitKit.cpp:229: void llvm::SplitAnalysis::calcLiveBlockInfo(): Assertion `LVI->end >= Stop && "range ends mid block with no uses"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0. Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/llc -o /app/output.s -x86-asm-syntax=intel
1. Running pass 'Function Pass Manager' on module ''.
2. Running pass 'Greedy Register Allocator' on function '@func_1'
#0 0x00000000042533c8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x42533c8)
#1 0x00000000042502a4 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#2 0x000072fd2d042520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#3 0x000072fd2d0969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
#4 0x000072fd2d042476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
#5 0x000072fd2d0287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
#6 0x000072fd2d02871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
#7 0x000072fd2d039e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#8 0x000000000340b349 llvm::SplitAnalysis::calcLiveBlockInfo() (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x340b349)
#9 0x000000000340b678 llvm::SplitAnalysis::analyzeUses() (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x340b678)
#10 0x000000000334616f llvm::RAGreedy::tryAssignCSRFirstTime(llvm::LiveInterval const&, llvm::AllocationOrder&, llvm::MCRegister, unsigned char&, llvm::SmallVectorImpl&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x334616f)
#11 0x000000000334d9cb llvm::RAGreedy::selectOrSplitImpl(llvm::LiveInterval const&, llvm::SmallVectorImpl&, llvm::SmallSet>&, llvm::SmallVector, 8u>&, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x334d9cb)
#12 0x000000000334e707 llvm::RAGreedy::selectOrSplit(llvm::LiveInterval const&, llvm::SmallVectorImpl&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x334e707)
#13 0x00000000035b60f0 llvm::RegAllocBase::allocatePhysRegs() (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x35b60f0)
#14 0x000000000334a2fb llvm::RAGreedy::run(llvm::MachineFunction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x334a2fb)
#15 0x000000000334af4a (anonymous namespace)::RAGreedyLegacy::runOnMachineFunction(llvm::MachineFunction&) RegAllocGreedy.cpp:0:0
#16 0x000000000310c569 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
#17 0x00000000037693a6 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x37693a6)
#18 0x0000000003769751 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x3769751)
#19 0x0000000003769fbf llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x3769fbf)
#20 0x00000000008ea452 compileModule(char**, llvm::SmallVectorImpl&, llvm::LLVMContext&, std::__cxx11::basic_string, std::allocator>&) llc.cpp:0:0
#21 0x00000000007c5c2c main (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x7c5c2c)
#22 0x000072fd2d029d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#23 0x000072fd2d029e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#24 0x00000000008df4f5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x8df4f5)
Program terminated with signal: SIGSEGV
Compiler returned: 139
```

Reproduce the crash with llc and the supplied LLVM IR, then inspect llvm/lib/CodeGen/SplitKit.cpp around SplitAnalysis::calcLiveBlockInfo and the Greedy Register Allocator path named in the stack dump. Done means the RISC-V testcase no longer triggers the assertion and has regression coverage.

Written by the indexing model from the issue text.