Adds a MachineFunctionPass that scans the body to find calls, and
update the register mask with the one saved by the
RegUsageInfoCollector analysis in PhysicalRegisterUsageInfo.
Patch by Vivek Pandya <vivekvpandya@gmail.com>
Differential Revision: http://reviews.llvm.org/D21180
llvm-svn: 272414
Mehdi Amini