Don't call llvm_start_multithreaded() during init.  As of LLVM
revision r211277, this function is essentially a no-op.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211285 91177308-0d34-0410-b5e6-96231b3b80d8
Document unroll and unroll_count directives.

Extend the documentation for "#pragma clang loop" hints to include the unroll
and unroll_count directives.

Patch by Mark Heffernan [http://reviews.llvm.org/D4198]



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211286 91177308-0d34-0410-b5e6-96231b3b80d8
Fix PR20069: bad loop pragma arguments crash FE

This patch fixes a crash when handling malformed arguments to loop pragmas such
as: "#pragma clang loop vectorize(()".  Essentially any argument which is not an
identifier or constant resulted in a crash.  This patch also changes a couple of
the error messages which weren't quite correct.  New behavior with this patch vs
old behavior:

#pragma clang loop vectorize(1)
OLD: error: missing keyword; expected 'enable' or 'disable'
NEW: error: invalid argument; expected 'enable' or 'disable'

#pragma clang loop vectorize()
OLD: error: expected ')'
NEW: error: missing argument to loop pragma 'vectorize'

#pragma clang loop vectorize_width(bad)
OLD: error: missing value; expected a positive integer value
NEW: error: invalid argument; expected a positive integer value

#pragma clang loop vectorize(bad)
OLD: invalid keyword 'bad'; expected 'enable' or 'disable'
NEW: error: invalid argument; expected 'enable' or 'disable'

http://reviews.llvm.org/D4197

Patch by Mark Heffernan



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211292 91177308-0d34-0410-b5e6-96231b3b80d8