C, -fexceptions, libgcc_s, and related matters on arm64

[Florian Weimer]

* John via Gcc-help Dallman:

> My arm64 compile options are similar: cc -march=armv8-a -ffp-contract=off -O -fPIC -D_POSIX_SOURCE -D_POSIX_C_SOURCE=200112L -c -fexceptions -std=c99 -Wformat -Wformat-security -fstack-protector-strong -fno-strict-aliasing
>
> Any suggestions?

Check -S output and see if references to the personality routine are
there.  Then proceed to the generated object files.

Maybe your AArch64 toolchain defaults to static linking?  Or the
compiler is not GCC and does not actually implement this GNU
extension?