[BACKPORT][ARM] PR ld/19368: Add missing relocation type class for R_ARM_IRELATIVE
    
    	Apply from master
    
    	2016-01-08  Richard Sandiford  <richard.sandiford@arm.com>
    		    Jiong Wang  <jiong.wang@arm.com>
    
    	bfd/
    	PR ld/19368
    	* elf32-arm.c (elf32_arm_reloc_type_class): Map R_ARM_IRELATIVE to
    	reloc_class_ifunc.
    
    	ld/testsuite/
    	* testsuite/ld-arm/ifunc-3.rd: Update expected result.
    	* testsuite/ld-arm/ifunc-4.rd: Likewise.
    	* testsuite/ld-arm/ifunc-9.rd: Likewise.
    	* testsuite/ld-arm/ifunc-10.rd: Likewise.
    	* testsuite/ld-arm/ifunc-12.rd: Likewise.
    	* testsuite/ld-arm/ifunc-13.rd: Likewise.