[Lex] Speed up updateConsecutiveMacroArgTokens (NFC)

SM.isWrittenInSameFile() calls getFileID(), which can be expensive.
Move this check behind some cheaper filters.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@274800 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Lex/TokenLexer.cpp

@@ -787,9 +787,6 @@ static void updateConsecutiveMacroArgTokens(SourceManager &SM,
     if (CurLoc.isFileID() != NextLoc.isFileID())
       break; // Token from different kind of FileID.
 
-    if (CurLoc.isMacroID() && !SM.isWrittenInSameFile(CurLoc, NextLoc))
-      break; // Token from a different macro.
-
     int RelOffs;
     if (!SM.isInSameSLocAddrSpace(CurLoc, NextLoc, &RelOffs))
       break; // Token from different local/loaded location.
@@ -797,6 +794,10 @@ static void updateConsecutiveMacroArgTokens(SourceManager &SM,
     // "characters" away.
     if (RelOffs < 0 || RelOffs > 50)
       break;
+
+    if (CurLoc.isMacroID() && !SM.isWrittenInSameFile(CurLoc, NextLoc))
+      break; // Token from a different macro.
+
     CurLoc = NextLoc;
   }