Re: PR16005, avr linker crash on a particular instruction sequence with --relax

The last patch wasn't so clever.  The contents in fact have already
been read, just not cached where relax_delete_bytes expects them.
relax_delete_bytes also modifies relocs and syms, so they should be
cached too.

	PR 16005
	* elf32-avr.c (elf32_avr_relax_delete_bytes): Revert last change.
	(elf32_avr_relax_section): Cache contents, relocs and syms
	before calling relax_delete_bytes.