preprocessor: Check for line number overflow

Also remove dead code in Tokenizer.l

BUG=chromium:668842

Change-Id: Ice18313a64f0bb2242299993bfaa882a6578ad54
Reviewed-on: https://chromium-review.googlesource.com/435042
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/compiler/preprocessor/Token.h b/src/compiler/preprocessor/Token.h
index 5e972ca..26732ab 100644
--- a/src/compiler/preprocessor/Token.h
+++ b/src/compiler/preprocessor/Token.h
@@ -19,7 +19,9 @@
 {
     enum Type
     {
-        LAST = 0,  // EOF.
+        // Calling this ERROR causes a conflict with wingdi.h
+        GOT_ERROR = -1,
+        LAST  = 0,  // EOF.
 
         IDENTIFIER = 258,