[LLVM][X86] Add EFLAGS Defs for VERR/VERW instructions (#81824)

VERR/VERW instructions will define ZF flag.

Author: ri-char

llvm/lib/Target/X86/X86InstrSystem.td

@@ -366,12 +366,14 @@ def LGS32rm : I<0xb5, MRMSrcMem, (outs GR32:$dst), (ins opaquemem:$src),
 def LGS64rm : RI<0xb5, MRMSrcMem, (outs GR64:$dst), (ins opaquemem:$src),
                  "lgs{q}\t{$src, $dst|$dst, $src}", []>, TB;
 
+let Defs = [EFLAGS] in {
 def VERRr : I<0x00, MRM4r, (outs), (ins GR16:$seg), "verr\t$seg", []>, TB;
 def VERWr : I<0x00, MRM5r, (outs), (ins GR16:$seg), "verw\t$seg", []>, TB;
 let mayLoad = 1 in {
 def VERRm : I<0x00, MRM4m, (outs), (ins i16mem:$seg), "verr\t$seg", []>, TB;
 def VERWm : I<0x00, MRM5m, (outs), (ins i16mem:$seg), "verw\t$seg", []>, TB;
 }
+} // Defs EFLAGS
 } // SchedRW
 
 //===----------------------------------------------------------------------===//