Call Frame Optimization on i386 and libunwind, by disallowing the
optimization for i386-freebsd12.
This should fix some instances of broken exception handling when frame
pointers are omitted, in particular some unittests run during the build
of editors/libreoffice.
This hack will be removed as soon as upstream has implemented a more
permanent fix for this problem.
Upstream PR: https://llvm.org/bugs/show_bug.cgi?id=30879
Reviewed by: emaste
PR: 212343
[X86] Convert esp-relative movs of function arguments to pushes, step 2
This moves the transformation introduced in r223757 into a separate MI pass.
This allows it to cover many more cases (not only cases where there must be a
reserved call frame), and perform rudimentary call folding. It still doesn't
have a heuristic, so it is enabled only for optsize/minsize, with stack
alignment <= 8, where it ought to be a fairly clear win.
(Re-commit of r227728)
Differential Revision: http://reviews.llvm.org/D6789
This helps to get sys/boot/i386/boot2 below the required size again,
when optimizing with -Oz.
