* config/tc-sh.c: Add support for sh4a and no-fpu variants,
with appropriate additions to md_show_usage.
* testsuite/gas/sh/basic.exp: Call tests for sh4a.
* testsuite/gas/sh/{err-sh4a-fp.s, err-sh4a.s,
err-sh4al-dsp.s, sh4a-dsp.d, sh4a-dsp.s, sh4a-fp.d,
sh4a-fp.s, sh4a.d, sh4a.s, sh4al-dsp.d, sh4al-dsp.s:
New files, tests for sh4a and related variants.
* doc/c-sh.texi: Document new -isa options.
* doc/c-sh64.texi: Ditto.
* NEWS: Mention new support for sh4a.