Add support for explicit constructor calls in Microsoft mode.
For example: 

class A{ 
public:
  A& operator=(const A& that) {
      if (this != &that) {
          this->A::~A();
          this->A::A(that);  // <=== explicit constructor call.
      }
      return *this;
  }
};

More work will be needed to support an explicit call to a template constructor.

llvm-svn: 123735
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 80ef65e..4bb9591 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -7904,7 +7904,11 @@
       if (isa<UsingShadowDecl>(Func))
         Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
 
-      if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
+      // Microsoft supports direct constructor calls.
+      if (getLangOptions().Microsoft && isa<CXXConstructorDecl>(Func)) {
+        AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs,
+                             CandidateSet);
+      } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
         // If explicit template arguments were provided, we can't call a
         // non-template member function.
         if (TemplateArgs)