[PATCH] Fix VGATHER* operand constraints

Add earlyclobber constaints to prevent input register being allocated as
the output register because, according to Intel spec [1], "If any pair
of the index, mask, or destination registers are the same, this
instruction results a UD fault."

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[1] http://software.intel.com/sites/default/files/319433-014.pdf



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183327 91177308-0d34-0410-b5e6-96231b3b80d8
Use IRBuilder instead of ConstantInt methods. It simplifies code a little bit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183328 91177308-0d34-0410-b5e6-96231b3b80d8
yaml2obj: add -format=<fmt> to choose input YAML interpretation

See the comment in yaml2obj.cpp for why this is currently needed.
Eventually we can get rid of this, but for now it is needed in order to
make forward progress with adding ELF support, and should be
straightforward to remove later.

Also, preserve the default of COFF, to avoid breaking existing tests.
This policy can easily be changed later though.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183332 91177308-0d34-0410-b5e6-96231b3b80d8