Re: LoongArch: Add support for <b ".L1"> and <beq, $t0, $t1, ".L1">

This fixes the buffer overflow added in commit 22b78fad28, and a few
other problems.

	* loongarch-coder.c (loongarch_split_args_by_comma): Don't
	overflow buffer when args == "".  Don't remove unbalanced
	quotes.  Don't trim last arg if max number of args exceeded.