Added LLVM_FALLTHROUGH to address warning: this statement may fall through. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@304652 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Basic/TargetInfo.cpp

@@ -143,9 +143,11 @@ const char *TargetInfo::getTypeConstantSuffix(IntType T) const {
   case UnsignedChar:
     if (getCharWidth() < getIntWidth())
       return "";
+    LLVM_FALLTHROUGH;
   case UnsignedShort:
     if (getShortWidth() < getIntWidth())
       return "";
+    LLVM_FALLTHROUGH;
   case UnsignedInt:      return "U";
   case UnsignedLong:     return "UL";
   case UnsignedLongLong: return "ULL";