Generate IMAGE_REL_AMD64_ADDR32NB relocations for SEH
 data structures.

The Win64 EH data structures must be of type IMAGE_REL_AMD64_ADDR32NB
instead of IMAGE_REL_AMD64_ADDR32. This is easiely achieved by adding
the VK_COFF_IMGREL32 modifier to the symbol reference.
Change also references to start and end of the SEH range of a function
as offsets to start of the function.

Reviewed by Jim Grosbach, Charles Davis and Nico Rieck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190766 91177308-0d34-0410-b5e6-96231b3b80d8
Fix alignment of unwind data.

For alignment purposes, the instruction array will always have an even
number of entries, with the final entry potentially unused (in which
case the array will be one longer than indicated by the count of unwind
codes field).

Reviewed by Anton Korobeynikov, Charles Davis and Nico Rieck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190767 91177308-0d34-0410-b5e6-96231b3b80d8
MC: Add support for '?' flags in .section directives

Summary:
The '?' flag uses the last section group if the last had a section
group.  We treat combining an explicit section group and the '?' as a
hard error.

This fixes PR17198.

Reviewers: rafael, bkramer

Reviewed By: bkramer

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1686

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190768 91177308-0d34-0410-b5e6-96231b3b80d8
ELF: Add support for the exclude section bit for gas compat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190769 91177308-0d34-0410-b5e6-96231b3b80d8