Fix return values of some matcher functions

The old return values mean

* implicit conversion
* not being able to write sizeOfExpr().bind() for example

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -2662,7 +2662,7 @@ AST_MATCHER_P(UnaryExprOrTypeTraitExpr, ofKind, UnaryExprOrTypeTrait, Kind) {
 
 /// Same as unaryExprOrTypeTraitExpr, but only matching
 /// alignof.
-inline internal::Matcher<Stmt> alignOfExpr(
+inline internal::BindableMatcher<Stmt> alignOfExpr(
     const internal::Matcher<UnaryExprOrTypeTraitExpr> &InnerMatcher) {
   return stmt(unaryExprOrTypeTraitExpr(
       allOf(anyOf(ofKind(UETT_AlignOf), ofKind(UETT_PreferredAlignOf)),
@@ -2671,7 +2671,7 @@ inline internal::Matcher<Stmt> alignOfExpr(
 
 /// Same as unaryExprOrTypeTraitExpr, but only matching
 /// sizeof.
-inline internal::Matcher<Stmt> sizeOfExpr(
+inline internal::BindableMatcher<Stmt> sizeOfExpr(
     const internal::Matcher<UnaryExprOrTypeTraitExpr> &InnerMatcher) {
   return stmt(unaryExprOrTypeTraitExpr(
       allOf(ofKind(UETT_SizeOf), InnerMatcher)));