[arm-embedded] Backport trunk thumb1 pic fix to embedded-4_8-branch

[Terry Guo]

Hi,

This patch back ported trunk fix at r205391 to arm/embedded-4_8-branch.

BR,
Terry

gcc/ChangeLog.arm
2013-11-27  Terry Guo  <terry....@arm.com>

        Backport mainline r205391
        2013-11-26  Terry Guo  <terry....@arm.com>

        * config/arm/arm.c (require_pic_register): Handle high pic base
        register for thumb-1.
        (arm_load_pic_register): Also initialize high pic base register.
        * doc/invoke.texi: Update documentation for option -mpic-register.

gcc/testsuite/ChangeLog.arm
2013-11-27  Terry Guo  <terry....@arm.com>

        Backport mainline r205391
        2013-11-26  Terry Guo  <terry....@arm.com>

        * gcc.target/arm/thumb1-pic-high-reg.c: New case.
        * gcc.target/arm/thumb1-pic-single-base.c: New case.