Refactor: Simplify boolean expresssions in lib/Lex

[LegalizeAdulthood]

Summary

Simplify boolean expressions using true and false with clang-tidy

[dblaikie]

Looks good - committed in r232999

cfe/trunk/lib/Lex/LiteralSupport.cpp

case 'x': { // Hex escape.
     }
 
     // Hex escapes are a maximal series of hex digits.
     bool Overflow = false;
     for (; ThisTokBuf != ThisTokEnd; ++ThisTokBuf) {
       int CharVal = llvm::hexDigitValue(ThisTokBuf[0]);
       if (CharVal == -1) break;
       // About to shift out a digit?
-      Overflow |= (ResultChar & 0xF0000000) ? true : false;
+      Overflow |= ResultChar & 0xF0000000;
       ResultChar <<= 4;
       ResultChar |= CharVal;
     }
 
     // See if any bits will be truncated when evaluated as a character.
     if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) {
       Overflow = true;
       ResultChar &= ~0U >> (32-CharWidth);