Support multiple COFF sections with the same name but different COMDAT.

This is the first step to fix pr17918.

It extends the .section directive a bit, inspired by what the ELF one looks
like. The problem with using linkonce is that given

.section foo
.linkonce....

.section foo
.linkonce

we would already have switched sections when getting to .linkonce. The cleanest
solution seems to be to add the comdat information in the .section itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195148 91177308-0d34-0410-b5e6-96231b3b80d8
DataLayout: value initialize globals to avoid static construction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195150 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-cov: Added constness property to methods.

Added constness to methods that shouldn't modify objects. Replaced
operator[] lookup in maps with find() instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195151 91177308-0d34-0410-b5e6-96231b3b80d8
reverts 195057 per request

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195152 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-cov: Moved printing after error checks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195153 91177308-0d34-0410-b5e6-96231b3b80d8
Make it explicit that nulls are not allowed in names.

The object files we support use null terminated strings, so there is no way to
support these.

This patch adds an assert to catch bad API use and an error check in the .ll
parser.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195155 91177308-0d34-0410-b5e6-96231b3b80d8
[DAG] Refactor vector splitting code in SelectionDAG. No functional change intended.

Reviewed by Tom

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195156 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Resolve relocation for the stubs in MCJIT when load address is known

Instead of processing relocation for branch to stubs right away, emit a
modified relocation and add it to queue to be resolved later when final load
address is known.
This resolves seven MIPS MCJIT issues that were caused by missing relocation
fixups at the end.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195157 91177308-0d34-0410-b5e6-96231b3b80d8
SLPVectorizer: Fix whitespace errors

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195161 91177308-0d34-0410-b5e6-96231b3b80d8
SLPVectorizer: Fix stale for Value pointer array

We are slicing an array of Value pointers and process those slices in a loop.
The problem is that we might invalidate a later slice by vectorizing a former
slice.

Use a WeakVH to track the pointer. If the pointer is deleted or RAUW'ed we can
tell.

The test case will only fail when running with libgmalloc.

radar://15498655

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195162 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Constify accelerator table handling, and separate type accelarator insertion in preparation for a second use of this code from type units.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195164 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Partial implementation of DWARF type units.

Emit DW_TAG_type_units into the debug_info section using compile unit
headers. This is bogus/unusable by debuggers, but testable and provides
more isolated review.

Subsequent patches will include support for type unit headers and
emission into the debug_types section, as well as comdat grouping the
types based on their hash. Also the CompileUnit type will be renamed
'Unit' and relevant portions pulled out into respective CompileUnit and
TypeUnit types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195166 91177308-0d34-0410-b5e6-96231b3b80d8