Fix r173881 to properly skip invalid UTF-8 characters in raw lexing and -E.

This caused hangs as we processed the same invalid byte over and over.

<rdar://problem/13115651>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173959 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 6a918d6..4b5a313 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -3538,6 +3538,7 @@
       return LexUnicode(Result, CodePoint, CurPtr);
     
     if (isLexingRawMode() || PP->isPreprocessedOutput()) {
+      ++CurPtr;
       Kind = tok::unknown;
       break;
     }