[gcc] Add clobber FLAGS_REG to NaCl indirect jumps

Compiler must know that NaCl indirect jump clobbers FLAGS register.

For call and return this is probably not important, as FLAGS is always clobbered by call.

For computed goto and switch, this IS important, so added explicit clobber.

TEST=very hard to reproduce, we only suspect this bug was the reason for LLVM miscompilation.


Review URL: http://codereview.chromium.org/3892003
1 file changed