buildgcc: Build GMP `--with-pic` if GCC defaults to `-pie`

GCC 6 can optionally default to building all binaries as position
independent executables (PIE). This breaks linking against static
libraries that are compiled without position independent code (PIC).

Building GMP `--with-pic` in this case seems to be the least fragile
solution.

TEST=Run `make all` and `make BUILDGCC_OPTIONS=-b build-i386` in
     util/crossgcc on Debian Stretch.

Change-Id: I5f3185af9c8d599379a628e18724b217b88be974
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/17936
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
1 file changed