This is needed when running the tests in Freestanding mode, where main()
isn't treated specially. In Freestanding, main() doesn't get mangled as
extern "C", so whatever runtime we're using fails to find the entry point.
One way to solve this problem is to define a symbol alias from __Z4mainiPPc
to _main, however this requires all definitions of main() to have the same
mangling. Hence this commit.
unw_getcontext() should return UNW_ESUCCESS on success. Therefore, the
assembly for AArch64 is incorrect because "ldr x0, #0" is a PC-relative
load instead of an immediate value load.
llvm-svn: 240648