* target-def.h (TARGET_HAVE_SRODATA_SECTION): New macro.
        * target.h (gcc_target): Add have_srodata_section member.
        * varasm.c (section_category): Add SECCAT_SRODATA.
        (categorize_decl_for_section): Return SECCAT_SRODATA for sdata if
        READONLY_SDATA_SECTION defined.
        (decl_readonly_section_1): True for SECCAT_SRODATA also.
        (default_elf_select_section_1): Map SECCAT_SRODATA to .sdata2.
        (default_unique_section_1): Likewise.

From-SVN: r56806