XFAIL the vector kernel args test also if _DEBUG is set.
LLVM 3.4: compiling blocks crashes Clang with multiple address
spaces. The patch fixes this. Will be submitting upstream.
Move PHINodes from the entries of the replicated
parallel regions to the entry of the first of the chain.

Fixes a regression test case that broke with LLVM 3.5 due to
this exposed bug.
Updated some interesting CHANGES from git log.
Add -pthread to LDFLAGS otherwise some tests fail to link
when compiling with some compilers such as Clang++ 3.4 or gcc 4.8.