[r14-5930 Regression] FAIL: gcc.c-torture/compile/libcall-2.c -Os (test for excess errors) on Linux/x86_64

["haochen.jiang" <haochenj@ecsmtp.sh.intel.com>]

On Linux/x86_64,

f31a019d1161ec78846473da743aedf49cca8c27 is the first bad commit
commit f31a019d1161ec78846473da743aedf49cca8c27
Author: Jose E. Marchesi <jose.marchesi@oracle.com>
Date:   Fri Nov 24 06:30:28 2023 +0100

    Emit funcall external declarations only if actually used.

caused

FAIL: gcc.c-torture/compile/libcall-2.c   -O0  (test for excess errors)
FAIL: gcc.c-torture/compile/libcall-2.c   -O1  (test for excess errors)
FAIL: gcc.c-torture/compile/libcall-2.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: gcc.c-torture/compile/libcall-2.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)
FAIL: gcc.c-torture/compile/libcall-2.c   -O2  (test for excess errors)
FAIL: gcc.c-torture/compile/libcall-2.c   -O3 -g  (test for excess errors)
FAIL: gcc.c-torture/compile/libcall-2.c   -Os  (test for excess errors)

with GCC configured with

../../gcc/configure --prefix=/export/users/haochenj/src/gcc-bisect/master/master/r14-5930/usr --enable-clocale=gnu --with-system-zlib --with-demangler-in-ld --with-fpmath=sse --enable-languages=c,c++,fortran --enable-cet --without-isl --enable-libmpx x86_64-linux --disable-bootstrap

To reproduce:

$ cd {build_dir}/gcc && make check RUNTESTFLAGS="compile.exp=gcc.c-torture/compile/libcall-2.c --target_board='unix{-m32}'"
$ cd {build_dir}/gcc && make check RUNTESTFLAGS="compile.exp=gcc.c-torture/compile/libcall-2.c --target_board='unix{-m32\ -march=cascadelake}'"

(Please do not reply to this email, for question about this report, contact me at haochen dot jiang at intel.com.)
(If you met problems with cascadelake related, disabling AVX512F in command line might save that.)
(However, please make sure that there is no potential problems with AVX512.)