Use SmallVectorImpl& for function arguments instead of SmallVector.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185715 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/TokenLexer.cpp b/lib/Lex/TokenLexer.cpp
index 4f21995..ded2b56 100644
--- a/lib/Lex/TokenLexer.cpp
+++ b/lib/Lex/TokenLexer.cpp
@@ -121,7 +121,7 @@
 
 /// Remove comma ahead of __VA_ARGS__, if present, according to compiler dialect
 /// settings.  Returns true if the comma is removed.
-static bool MaybeRemoveCommaBeforeVaArgs(SmallVector<Token, 128> &ResultToks,
+static bool MaybeRemoveCommaBeforeVaArgs(SmallVectorImpl<Token> &ResultToks,
                                          bool &NextTokGetsSpace,
                                          bool HasPasteOperator,
                                          MacroInfo *Macro, unsigned MacroArgNo,