[PATCH] Introduce Parser::completeExpression.

[Samuel Benzaquen]

================
Comment at: lib/ASTMatchers/Dynamic/Parser.cpp:294
@@ -262,2 +293,3 @@
             << CommaToken.Text;
+        ContextStack.pop_back();
         return false;
----------------
Can you add a scoped object that will pop_back automatically?

================
Comment at: lib/ASTMatchers/Dynamic/Parser.cpp:388
@@ +387,3 @@
+  // We cannot complete code if there is an invalid element on the context
+  // stack.
+  for (ContextStackTy::iterator I = ContextStack.begin(),
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Is there a good use case for not aborting the parse if lookupMatcherCtor() returns null?
(instead of pushing it into the stack and then checking if there is a null in the stack)


http://llvm-reviews.chandlerc.com/D2261