[AMDGPU] Fix out of bound physreg tuple condition. NFC. (llvm#152777)

The end register of the tuple shall be below the last existing
register. The check does not work on something like {v[255:256]}.
Overall it works correctly because if fails later at the
getMatchingSuperReg() call.

Author: rampitec

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

@@ -16925,7 +16925,7 @@ SITargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI_,
 
     if (RC) {
       if (NumRegs > 1) {
-        if (Idx >= RC->getNumRegs() || Idx + NumRegs - 1 > RC->getNumRegs())
+        if (Idx >= RC->getNumRegs() || Idx + NumRegs - 1 >= RC->getNumRegs())
           return std::pair(0U, nullptr);
 
         uint32_t Width = NumRegs * 32;