MSP430 Assembler: Define symbols for functions to run through.

MSP430 Assembler: Define symbols for functions to run through.

gas	* config/tc-msp430.c (msp430_make_init_symbols): Define
	__crt0_run_{preinit,init,fini}_array symbols if
	.{preinit,init,fini}_array sections exist.
	* testsuite/gas/msp430/fini-array.d: New test.
	* testsuite/gas/msp430/init-array.d: New test.
	* testsuite/gas/msp430/preinit-array.d: New test.
	* testsuite/gas/msp430/fini-array.s: New test source.
	* testsuite/gas/msp430/init-array.s: New test source.
	* testsuite/gas/msp430/preinit-array.s: New test source.
	* testsuite/gas/msp430/msp430.exp: Add new tests to driver.