mips.c (machine_function): Add initialized_mips16_gp_pseudo_p.

mips.c (machine_function): Add initialized_mips16_gp_pseudo_p.

gcc/
	* config/mips/mips.c (machine_function): Add
	initialized_mips16_gp_pseudo_p.
	(mips16_gp_pseudo_reg): Do not emit the initialization of
	mips16_gp_pseudo_rtx when being called from the gimple cost-
	calculation routines; emit it on the first use outside those
	routines.

From-SVN: r126919