[Bug target/70955] regression in code generation for __builtin_ms_va_list in GCC 6.1

["zenith432 at users dot sourceforge.net" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70955

zenith432 at users dot sourceforge.net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |target

--- Comment #3 from zenith432 at users dot sourceforge.net ---
This only happens when compiling with -flto.

Attached is a standalone sample (va_main.c + va_test.c)

gcc -v
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/6.1.1/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-linker-hash-style=gnu --enable-plugin --enable-initfini-array
--disable-libgcj --with-isl --enable-libmpx --enable-gnu-indirect-function
--with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 6.1.1 20160427 (Red Hat 6.1.1-1) (GCC) 

gcc -o prog va_main.c va_test.c
./prog
sum == 15

gcc -o prog_flto -flto va_main.c va_test.c
./prog_flto
Segmentation fault (core dumped)