Add -static-pie to GCC driver to create static PIE

Add -static-pie to GCC driver to create static PIE

This patch adds -static-pie to GCC driver to create static PIE.  A static
position independent executable (PIE) is similar to static executable,
but can be loaded at any address without a dynamic linker.  All linker
input files must be compiled with -fpie or -fPIE and linker must support
--no-dynamic-linker to avoid linking with dynamic linker.  "-z text" is
also needed to prevent dynamic relocations in read-only segments.

	PR driver/81498
	* common.opt (-static-pie): New alias.
	(shared): Negate static-pie.
	(-no-pie): Update help text.
	(-pie): Likewise.
	(static-pie): New option.
	* config/gnu-user.h (GNU_USER_TARGET_STARTFILE_SPEC): Add
	-static-pie support.
	(GNU_USER_TARGET_ENDFILE_SPEC): Likewise.
	(LINK_EH_SPEC): Likewise.
	(LINK_GCC_C_SEQUENCE_SPEC): Likewise.
	* config/i386/gnu-user.h (GNU_USER_TARGET_LINK_SPEC): Likewise.
	* config/i386/gnu-user64.h (GNU_USER_TARGET_LINK_SPEC): Likewise.
	* gcc.c (LINK_COMMAND_SPEC): Likewise.
	(init_gcc_specs): Likewise.
	(init_spec): Likewise.
	(display_help): Update help message for -pie.
	* doc/invoke.texi: Update -pie, -no-pie and -static.  Document
	-static-pie.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252034 138bc75d-0d04-0410-961f-82ee72b054a4