Add a special BuildVirtualCall that's going to be used for building calls to destructors. This is needed because when compiling:

struct A {
	virtual ~A();
};

void f(A* a) {
	delete a;
}

A's deleting destructor should be called.

llvm-svn: 87083

generated PHI node for the null check of a new operator.

llvm-svn: 86738

llvm-svn: 83195

"usual deallocation function" with two arguments. CodeGen will have to
handle this case specifically, since the value for the second argument
(the size of the allocated object) may have to be computed at run
time.

Fixes the Sema part of PR4782.

llvm-svn: 83080

llvm-svn: 82642

llvm-svn: 82628

llvm-svn: 82585