Add support for ARM's NOREAD section flag.

Add support for ARM's NOREAD section flag.

include/elf
     * arm.h: Add arm SHF_ARM_NOREAD section flag.

bfd  * bfd-in2.h: Regenerate.
     * section.c: Add SEC_ELF_NOREAD.
     * elf32-arm.c (elf32_arm_post_process_headers): Only set
     PF_X attribute if a segment only contains section with
     SHF_ARM_NOREAD flag.
     (elf32_arm_fake_sections): Add SEC_ELF_NOREAD conversion.
     (elf32_arm_section_flags): New function to convert SHF_ARM_NOREAD
     to bfd flag.
     (elf32_arm_lookup_section_flags): New function to allow
     INPUT_SECTION_FLAGS directive with SHF_ARM_NOREAD flag.
     (elf32_arm_special_sections): Add special sections array
     to catch section prefix by '.text.noread' pattern.

ld/testsuite
     * ld-arm/arm-elf.exp: New tests.
     * ld-arm/thumb1-input-section-flag-match.d: New
     * ld-arm/thumb1-input-section-flag-match.s: New
     * ld-arm/thumb1-noread-not-present-mixing-two-section.d: New
     * ld-arm/thumb1-noread-not-present-mixing-two-section.s: New
     * ld-arm/thumb1-noread-present-one-section.d: New
     * ld-arm/thumb1-noread-present-one-section.s: New
     * ld-arm/thumb1-noread-present-two-section.d: New
     * ld-arm/thumb1-noread-present-two-section.s: New

binutils
	* readelf.c (get_elf_section_flags): Add support for ARM specific
	section flags.