[llvm] Fix build break when building RISCVInstrInfo.cpp with MSVC (PR #110342)

[Daniel Paoliello via llvm-commits]

https://github.com/dpaoliello created https://github.com/llvm/llvm-project/pull/110342

After #109774 MSVC is failing to build LLVM with the error:

```
llvm\lib\Target\RISCV\RISCVInstrInfo.cpp(782): warning C4018: '<': signed/unsigned mismatch
```

Fix is ensure that the RHS is an unsigned integer.

>From dc7e0a6dae2510cad4a3fef56559aba02a3008a4 Mon Sep 17 00:00:00 2001
From: Daniel Paoliello <danpao at microsoft.com>
Date: Fri, 27 Sep 2024 16:49:24 -0700
Subject: [PATCH] Fix build break when building RISCVInstrInfo.cpp with MSVC

---
 llvm/lib/Target/RISCV/RISCVInstrInfo.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
index f0295d289ed86a..529944044f02d2 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -779,7 +779,7 @@ MachineInstr *RISCVInstrInfo::foldMemoryOperandImpl(
     if (RISCV::getRVVMCOpcode(MI.getOpcode()) == RISCV::VMV_X_S) {
       unsigned Log2SEW =
           MI.getOperand(RISCVII::getSEWOpNum(MI.getDesc())).getImm();
-      if (STI.getXLen() < (1 << Log2SEW))
+      if (STI.getXLen() < (1U << Log2SEW))
         return nullptr;
       switch (Log2SEW) {
       case 3: