[ms-cxxabi] Implement member pointer conversions

Summary:
This only supports converting along non-virtual inheritance paths by
changing the field offset or the non-virtual base adjustment.

This implements three kinds of conversions:
- codegen for Value conversions
- Constant emission for APValue
- Constant folding for CastExprs

In almost all constant initialization settings
EmitMemberPointer(APValue) is called, except when the expression
contains a reinterpret cast.

reinterpret casts end up being a big corner case because the null value
changes between different kinds of member pointers.

Reviewers: rsmith

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D741

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@181543 91177308-0d34-0410-b5e6-96231b3b80d8
ArrayRef'ize some SemaOverload methods

Patch by Robert Wilhelm.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@181544 91177308-0d34-0410-b5e6-96231b3b80d8
Add pragma-comment.c test case for r181426 that I forgot to add

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@181546 91177308-0d34-0410-b5e6-96231b3b80d8
Documentation warning: \param, not \parm


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@181550 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Simply & constrain test(s) for PR9600/PR9608

Both these tests were ultimately fixed by the check for
"isIncompleteType" & neither test case was really reduced to a minimal
form. On doing so it becomes apparent that the problem wasn't specific
to templates at all, so I've moved the test case to a more appropriate
test file and added FileCheck verification to it (to show the forward
declaration of the array element type as well as the array alignment and
size being 0 since it cannot be computed). That's about as far down this
rabbithole as I'm willing to go today, so the rest of the un-FileChecked
tests in test/CodeGenCXX/debug-info.cpp will have to go another day
without actually testing anything other than the fact that they don't
crash.

& improve the actually interesting test case in
test/CodeGenCXX/debug-info-templates.cpp which was my original goal (in
preparation for expanding it/fixing some related bugs in non-type
template parameters)

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@181552 91177308-0d34-0410-b5e6-96231b3b80d8
C++1y n3648: parse and reject init-captures for now.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@181553 91177308-0d34-0410-b5e6-96231b3b80d8