This takes advantage of the implicit default behavior to reduce the number of
attributes, which in turns reduces compilation time. I've observed -3% in
instruction count when compiling sqlite3 amalgamation with -O0
Differential Revision: https://reviews.llvm.org/D96400
Add OCL option -cl-no-signed-zeros to driver options.
Also added to opencl.cl testcases.
Patch by Aaron En Ye Shi.
Differential Revision: http://reviews.llvm.org/D22067
llvm-svn: 274923