Implement pointer to member handling in static_cast.
Fix a stupid mistake in UnwrapSimilarPointers that made any two member pointers compatible as long as the pointee was the same.
Make a few style corrections as suggested by Chris.

llvm-svn: 63215
diff --git a/clang/test/SemaCXX/member-pointer.cpp b/clang/test/SemaCXX/member-pointer.cpp
index bcd3dd6..31973c1 100644
--- a/clang/test/SemaCXX/member-pointer.cpp
+++ b/clang/test/SemaCXX/member-pointer.cpp
@@ -36,4 +36,7 @@
   // Fail conversion due to ambiguity and virtuality.
   int F::*pdif = pdi1; // expected-error {{ambiguous conversion from pointer to member of base class 'struct A' to pointer to member of derived class 'struct F'}} expected-error {{incompatible type}}
   int G::*pdig = pdi1; // expected-error {{conversion from pointer to member of class 'struct A' to pointer to member of class 'struct G' via virtual base 'struct D' is not allowed}} expected-error {{incompatible type}}
+
+  // Conversion to member of base.
+  pdi1 = pdid; // expected-error {{incompatible type assigning 'int struct D::*', expected 'int struct A::*'}}
 }