Silence Clang's -Wlogical-op-parentheses warning.

I'm not sure it's really worth expressing this as a range rather than 3 specific equalities, but it doesn't seem fundamentally wrong either.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157398 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AsmParser/LLLexer.cpp

@@ -678,7 +678,7 @@ lltok::Kind LLLexer::Lex0x() {
   CurPtr = TokStart + 2;
 
   char Kind;
-  if (CurPtr[0] >= 'K' && CurPtr[0] <= 'M' || CurPtr[0] == 'H') {
+  if ((CurPtr[0] >= 'K' && CurPtr[0] <= 'M') || CurPtr[0] == 'H') {
     Kind = *CurPtr++;
   } else {
     Kind = 'J';