K 10
svn:author
V 3
cem
K 8
svn:date
V 27
2019-11-05T03:20:40.476319Z
K 7
svn:log
V 740
Fix llvm-libunwind userspace build on ARM

GCC's libgcc exports a few ARM-specific symbols for ARM EABI, AEABI, or
EHABI or whatever it's called.  Export the same ones from LLVM-libunwind's
libgcc_s, on ARM.  As part of this, convert libgcc_s from a direct
Version.map to one constructed from component Symbol.map files.  This allows
the ARM-specific Symbol.map to be included only on ARM.

Fix ARM-only oddities in struct name/aliases in LLVM-libunwind to match
non-ARM definitions and ARM-specific expectations in libcxxrt /
libcompiler_rt.

No functional change intended for non-ARM architectures.

This commit does not actually flip the switch for ARM defaults from libgcc
to llvm-libunwind, but makes it possible (to compile, anyway).

END