middle-end/117433 - ICE with gimple BLKmode reg copy

middle-end/117433 - ICE with gimple BLKmode reg copy

When we end up expanding a SSA name copy with BLKmode regs which can
happen for vectors, possibly wrapped in a NOP-conversion or
a PAREN_EXPR and we are not optimizing we can end up with two
BLKmode MEMs that expand_gimple_stmt_1 doesn't properly handle
when expanding, trying to emit_move_insn them.  Looking at store_expr
which what expand_gimple_stmt_1 is really doing reveals a lot of
magic that's missing.  It eventually falls back to emit_block_move
(store_expr isn't exported), so this is what I ended up using here
given I think we'll only have BLKmode "registers" for vectors.

	PR middle-end/117433
	* cfgexpand.cc (expand_gimple_stmt_1): Use emit_block_move
	when moving temp to BLKmode target.

	* gcc.dg/pr117433.c: New testcase.