linux.h (TARGET_OS_CPP_BUILTINS): Remove definition of _GNU_SOURCE.

linux.h (TARGET_OS_CPP_BUILTINS): Remove definition of _GNU_SOURCE.

        * config/xtensa/linux.h (TARGET_OS_CPP_BUILTINS): Remove definition of
        _GNU_SOURCE.  Add definitions of __PIC__ and __pic__.
        (SUBTARGET_CPP_SPEC): Define.
        (LIB_SPEC): Delete.
        * config/xtensa/xtensa-protos.h (xtensa_declare_object): Delete.
        * config/xtensa/xtensa.c (xtensa_declare_object): Delete.
        * config/xtensa/xtensa.h (CPP_SPEC, SUBTARGET_CPP_SPEC, EXTRA_SPECS):
        Define.
        (ASM_OUTPUT_COMMON, ASM_OUTPUT_LOCAL): Delete.
        (ASM_OUTPUT_ALIGNED_BSS, BSS_SECTION_ASM_OP): Define.

From-SVN: r66083