msp430.c (msp430_attr): Produce an error if a static interrupt handler is detected.

	* config/msp430/msp430.c (msp430_attr): Produce an error if a
	static interrupt handler is detected.
	* config/msp430/msp430.h (LIB_SPEC): Do not use msp430.ld as the
	default linker script.
	* config/msp430/msp430.md (movpsihi2_lo): New pattern for loading
	the low part of a symbolic pointer.

From-SVN: r236704