Add powerpc to LLD_ARCH, and bump _SYSTEM_VERSION-powerpc so people
will upgrade to lld-linked packages when they exist. Remove
-Wl,--relax from several ports; ld.bfd needed this flag, but ld.lld
can't take it.
lang/gcc/8 needs USE_LLD = No, because LLD can't link C++ code from
gcc (error: relocation refers to a discarded section: ...), and also,
the adastrap is too old.
To avoid linker errors on macppc, you need a snapshot where
/usr/bin/ld is LLD.
ok sthen@
087bd55e9c