Add --[no-]map-whole-files for gold compatibility

Add --[no-]map-whole-files for gold compatibility

Gold supports:

  --map-whole-files           Map whole files to memory (default on 64-bit hosts)
  --no-map-whole-files        Map relevant file parts to memory (default on 32-bit hosts)

This patch adds --[no-]map-whole-files command line options for gold
compatibility.  They are ignored for ld.

	* lexsup.c (ld_options): Add --[no-]map-whole-files for gold
	option compatibility.