Removing the static initializer in ManagedStatic.cpp by using llvm_call_once to initialize the ManagedStatic mutex.

Summary:
This patch adds an llvm_call_once which is a wrapper around std::call_once on platforms where it is available and devoid of bugs. The patch also migrates the ManagedStatic mutex to be allocated using llvm_call_once.

These changes are philosophically equivalent to the changes added in r219638, which were reverted due to a hang on Win32 which was the result of a bug in the Windows implementation of std::call_once.

Reviewers: aaron.ballman, chapuni, chandlerc, rnk

Reviewed By: rnk

Subscribers: majnemer, llvm-commits

Differential Revision: http://reviews.llvm.org/D5922

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220932 91177308-0d34-0410-b5e6-96231b3b80d8
Fix incorrect invariant check in DAG Combine

Earlier this summer I fixed an issue where we were incorrectly combining
multiple loads that had different constraints such alignment, invariance,
temporality, etc. Apparently in one case I made copt paste error and swapped
alignment and invariance.

Tests included.

rdar://18816719

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220933 91177308-0d34-0410-b5e6-96231b3b80d8
llvm/test/Transforms/SampleProfile/syntax.ll: Relax MISSING-FILE not to
check locale-aware message catalog.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220934 91177308-0d34-0410-b5e6-96231b3b80d8
EXPORTED_SYMBOL_FILE using mingw and cmake

Summary: This is a fix for the command line syntax error while building LTO when using MinGW.

Patch By: jsroemer

Reviewers: rnk

Reviewed By: rnk

Subscribers: rnk, beanz, llvm-commits

Differential Revision: http://reviews.llvm.org/D5476

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220935 91177308-0d34-0410-b5e6-96231b3b80d8