Remove ancient hack that was emulating move semantics with reference counting.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217808 91177308-0d34-0410-b5e6-96231b3b80d8
Add return that was lost somehow in my last commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217810 91177308-0d34-0410-b5e6-96231b3b80d8
MC: Add support for BigObj

Teach WinCOFFObjectWriter how to write -mbig-obj style object files;
these object files allow for more sections inside an object file.

Our support for BigObj is notably different from binutils and cl: we
implicitly upgrade object files to BigObj instead of asking the user to
compile the same file *again* but with another flag.  This matches up
with how LLVM treats ELF variants.

This was tested by forcing LLVM to always emit BigObj files and running
the entire test suite.  A specific test has also been added.

I've lowered the maximum number of sections in a normal COFF file,
VS "14" CTP 3 supports no more than 65279 sections.  This is important
otherwise we might not switch to BigObj quickly enough, leaving us with
a COFF file that we couldn't link.

yaml2obj support is all that remains to implement.

Differential Revision: http://reviews.llvm.org/D5349

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217812 91177308-0d34-0410-b5e6-96231b3b80d8
Replace dead links to "Hacker's Delight" with general references. NFC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217814 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Start fixing our emission of ADDSUBPS and ADDSUBPD instructions by
introducing a synthetic X86 ISD node representing this generic
operation.

The relevant patterns for mapping these nodes into the concrete
instructions are also added, and a gnarly bit of C++ code in the
target-specific DAG combiner is replaced with simple code emitting this
primitive.

The next step is to generically combine blends of adds and subs into
this node so that we can drop the reliance on an SSE4.1 ISD node
(BLENDI) when matching an SSE3 feature (ADDSUB).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217819 91177308-0d34-0410-b5e6-96231b3b80d8