Reapply "[MachineScheduler] Fix for PR21807: minor code difference building with/without -g."

This reapplies r224118 with a fix for test 'misched-code-difference-with-debug.ll'.
That test was failing on some buildbots because it was x86 specific but it was
missing a target triple.
Added an explicit triple to test misched-code-difference-with-debug.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224126 91177308-0d34-0410-b5e6-96231b3b80d8
[AVX512] Enabling MIN/MAX lowering.
Added lowering tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224127 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Enable code generation for MIPS-III.

Summary:
This commit enables the MIPS-III target and adds support for code
generation of SELECT nodes. We have to use pseudo-instructions with
custom inserters for these nodes as MIPS-III CPUs do not have
conditional-move instructions.

Depends on D6212

Reviewers: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6464

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224128 91177308-0d34-0410-b5e6-96231b3b80d8
Require python 2.7.

We were already requiring 2.5, which meant that people on old linux distros
had to upgrade anyway.

Requiring python 2.6 will make supporting 3.X easier as we can use the 3.X
exception syntax.

According to the discussion on llvmdev, there is not much value is requiring
just 2.6, we may as well just require 2.7.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224129 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we require a newer python, use the new exception syntax.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224130 91177308-0d34-0410-b5e6-96231b3b80d8