[PATCH v2] gcc/config/rs6000: Add link with libc128 with -mlong-double-128 for AIX

[CHIGOT, CLEMENT via Gcc-patches]

Description:
 * AIX applications using 128-bit long double must be linked with
   libc128.a, in order to have 128-bit compatible routines.

Tests:
 * AIX 7.2, 7.1, 6.1: Build/Tests: OK

Changelog:
2020-04-03 Clément Chigot <clement.chi...@atos.net>
 * config/rs6000/aix61.h (LIB_SPEC): Add -lc128 with -mlong-double-128.
 * config/rs6000/aix71.h (LIB_SPEC): Likewise.
 * config/rs6000/aix72.h (LIB_SPEC): Likewise.

gcc-8.4.0-gcc-config-rs6000-add-link-with-libc128-with-mlong-d.patch
Description: gcc-8.4.0-gcc-config-rs6000-add-link-with-libc128-with-mlong-d.patch