[Preprocessor] Correct internal token parsing of newline characters i…

…n CRLF

Correct implementation:  Apparently I managed in r311683 to submit the wrong
version of the patch for this, so I'm correcting it now.

Differential Revision: https://reviews.llvm.org/D37079

llvm-svn: 312542

clang/lib/Lex/Lexer.cpp

@@ -3071,10 +3071,11 @@ bool Lexer::LexTokenInternal(Token &Result, bool TokAtPhysicalStartOfLine) {
     Kind = tok::unknown;
     break;
 
-  case '\n':
   case '\r':
-    if (CurPtr[0] != Char && (CurPtr[0] == '\n' || CurPtr[0] == '\r'))
+    if (CurPtr[0] == '\n')
       Char = getAndAdvanceChar(CurPtr, Result);
+    LLVM_FALLTHROUGH;
+  case '\n':
     // If we are inside a preprocessor directive and we see the end of line,
     // we know we are done with the directive, so return an EOD token.
     if (ParsingPreprocessorDirective) {