Add member template 'Type::getAs<T>', which converts a Type* to a respective T*.
This method is intended to eventually replace the individual
Type::getAsXXXType<> methods.

The motivation behind this change is twofold:

1) Reduce redundant implementations of Type::getAsXXXType() methods. Most of
them are basically copy-and-paste.

2) By centralizing the implementation of the getAs<Type> logic we can more
smoothly move over to Doug Gregor's proposed canonical type smart pointer
scheme.

Along with this patch:

a) Removed 'Type::getAsPointerType()'; now clients use getAs<PointerType>.
b) Removed 'Type::getAsBlockPointerTypE()'; now clients use getAs<BlockPointerType>.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76098 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 144dc50..b3de60a 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -136,7 +136,7 @@
   //   to an incomplete type other than (cv) void the program is ill-formed.
   QualType Ty = E->getType();
   int isPointer = 0;
-  if (const PointerType* Ptr = Ty->getAsPointerType()) {
+  if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
     Ty = Ptr->getPointeeType();
     isPointer = 1;
   }
@@ -708,7 +708,7 @@
       return ExprError(Diag(StartLoc, diag::err_delete_operand)
         << Type << Ex->getSourceRange());
 
-    QualType Pointee = Type->getAsPointerType()->getPointeeType();
+    QualType Pointee = Type->getAs<PointerType>()->getPointeeType();
     if (Pointee->isFunctionType() || Pointee->isVoidType())
       return ExprError(Diag(StartLoc, diag::err_delete_operand)
         << Type << Ex->getSourceRange());
@@ -812,7 +812,7 @@
   // string literal can be converted to an rvalue of type "pointer
   // to wchar_t" (C++ 4.2p2).
   if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From))
-    if (const PointerType *ToPtrType = ToType->getAsPointerType())
+    if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
       if (const BuiltinType *ToPointeeType 
           = ToPtrType->getPointeeType()->getAsBuiltinType()) {
         // This conversion is considered only when there is an
@@ -1066,7 +1066,7 @@
   //   such a class]
   QualType LType = lex->getType();
   if (isIndirect) {
-    if (const PointerType *Ptr = LType->getAsPointerType())
+    if (const PointerType *Ptr = LType->getAs<PointerType>())
       LType = Ptr->getPointeeType().getNonReferenceType();
     else {
       Diag(Loc, diag::err_bad_memptr_lhs)
@@ -1515,8 +1515,8 @@
   llvm::SmallVector<unsigned, 4> QualifierUnion;
   QualType Composite1 = T1, Composite2 = T2;
   const PointerType *Ptr1, *Ptr2;
-  while ((Ptr1 = Composite1->getAsPointerType()) &&
-         (Ptr2 = Composite2->getAsPointerType())) {
+  while ((Ptr1 = Composite1->getAs<PointerType>()) &&
+         (Ptr2 = Composite2->getAs<PointerType>())) {
     Composite1 = Ptr1->getPointeeType();
     Composite2 = Ptr2->getPointeeType();
     QualifierUnion.push_back(