Implements the thisExpr matcher.
Patch by Gabor Horvath.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166477 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/ASTMatchers/ASTMatchersTest.cpp b/unittests/ASTMatchers/ASTMatchersTest.cpp
index 5c97f3a..a97e90d 100644
--- a/unittests/ASTMatchers/ASTMatchersTest.cpp
+++ b/unittests/ASTMatchers/ASTMatchersTest.cpp
@@ -1333,6 +1333,13 @@
                  Constructor1Arg));
 }
 
+TEST(Matcher,ThisExpr) {
+  EXPECT_TRUE(
+      matches("struct X { int a; int f () { return a; } };", thisExpr()));
+  EXPECT_TRUE(
+      notMatches("struct X { int f () { int a; return a; } };", thisExpr()));
+}
+
 TEST(Matcher, BindTemporaryExpression) {
   StatementMatcher TempExpression = bindTemporaryExpr();