llvm-c: Return NULL from LLVMGetFirstTarget instead of asserting

If no targets are registered, LLVMGetFirstTarget currently fails with
an assertion. This patch makes it return NULL instead, similarly to
how LLVMGetNextTarget would.

Patch by Peter Zotov

Differential Revision: http://llvm-reviews.chandlerc.com/D1908



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192878 91177308-0d34-0410-b5e6-96231b3b80d8
Changing DebugInfoFinder to iterate over all the compile units.
Solves http://llvm.org/bugs/show_bug.cgi?id=17507

Committed on behalf of alon.mishne@intel.com

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192879 91177308-0d34-0410-b5e6-96231b3b80d8
[mips][msa] Correct definition order of ftrunc_[su], ftint_[su], and ftq.

Define these three instructions in alphabetical order (like the rest of the
file).
No functional change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192880 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-c: Don't assert in LLVMTargetMachineEmitToFile on nonexistent file

Error handling code for raw_fd_ostream constructor is present, but
never used, because formatted_raw_ostream will always assert on closed
fd's before.

Patch by Peter Zotov

Differential Revision: http://llvm-reviews.chandlerc.com/D1909



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192881 91177308-0d34-0410-b5e6-96231b3b80d8
[msan] Use zero-extension in shadow cast by default.

Switch to sign-extension in r192575 caused 7% perf loss on 482.sphinx3.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192882 91177308-0d34-0410-b5e6-96231b3b80d8