ld: Discard .rel.* and .rela.* sections

ld: Discard .rel.* and .rela.* sections

On many targets, like x86, .rel.dyn/.rela.dyn section is combined from
different .rel/.rela sections by -z combreloc.  To discard dynamic
relocation section, we need to discard .rel.* and .rela.* sections
instead of .rel.dyn and .rela.dyn sections.

Note: This test fails for targets which issue a warning when dynamic
section is discarded.

	* testsuite/ld-elf/reloc-discard.ld: Discard .rel.* and .rela.*
	sections instead of .rel.dyn and .rela.dyn sections.