Find arm-linux-gnueabi(hf)?-gcc in compile

Find arm-linux-gnueabi(hf)?-gcc in compile

GCC for arm-linux has different names on different distros.  It is
arm-linux-gnu-gcc on fedora.  Debian/Ubuntu has arm-linux-gnueabihf-gcc
and arm-linux-gnueabi-gcc.  So when I run gdb.compile/ tests on arm-linux,
I get,

(gdb) compile code -- ;
Could not find a compiler matching "^arm(-[^-]*)?-linux(-gnu)?-gcc$"

This patch extend the regexp to match both arm-linux-gnu-gcc and
arm-linux-gnueabihf-gcc.

gdb:

2018-01-19  Yao Qi  <yao.qi@linaro.org>

	* osabi.c (gdb_osabi_names): Extend the regexp for
	arm-linux-gnueabihf and arm-linux-gnueabi.