Changes

Attributes: Check declarations for dereferenceable bytes

This will allow tablegen to start directly marking intrinsics as
dereferenceable in a useful way. Not sure if callsites should override
or use the max.

[flang] Diagnose invalid initializations

f18 current ignores attempts to initialize (with =expr) things
that are not objects, or allows meaningless initializations of
things that have mistakenly been promoted to be objects.
Fix by refusing to promote to objects names that have any
attributes that cannot be applied to objects, and then catch
data initializations of symbols that are not objects.

Differential Revision: https://reviews.llvm.org/D142766

[flang][MSVC] Disable test on Windows

A test is crashing the compiler unexpectedly when built with MSVC;
disable it with an XFAIL until it can be analyzed further.

AMDGPU: Don't insert pointer bitcasts for printf lowering

Cleanup leftover typed pointer handling.