MIPS: Fix __builtin_longjmp (PR 64242)

MIPS: Fix __builtin_longjmp (PR 64242)

The problem here is mips has its own builtin_longjmp
pattern and it was not fixed when expand_builtin_longjmp
was fixed.  We need to read the new fp and gp before
restoring the stack as the buffer might be a local
variable.

2020-08-25  Andrew Pinski  <apinski@marvell.com>

gcc/ChangeLog:

	PR middle-end/64242
	* config/mips/mips.md (builtin_longjmp): Restore the frame
	pointer and stack pointer and gp.