Allow more lookup of types in dependent base classes

MSVC appears to perform name lookup into dependent base classes when the
dependent base class has a known primary template.  This allows them to
know whether some unqualified ids are types or not, which allows them to
parse more class templates without typename keywords.

We can do the same thing when type name lookup fails, and if we find a
single type decl in one of our dependent base classes, recover as though
the user wrote 'typename MyClass::TypeFromBase'.

This allows us to parse some COM smart pointer classes in wrl/client.h
from the Windows 8 SDK.

Reviewers: rsmith

Differential Revision: http://reviews.llvm.org/D4237

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@212561 91177308-0d34-0410-b5e6-96231b3b80d8
test: merge arm-intrin into ms-intrin, fix invocation

This merges the two tests into one since there is no real reason to separate
them.  It also fixes the test invocation to specify -fms-compatibility without
which we would end up without an Intrin.h header.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@212563 91177308-0d34-0410-b5e6-96231b3b80d8
Remove unnecessary check for NULL

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@212564 91177308-0d34-0410-b5e6-96231b3b80d8