aarch64: ilp32 testsuite fixes

aarch64: ilp32 testsuite fixes

This fixes test failures on ilp32 introduced in
r11-3032-gd4febc75e8dfab23bd3132d5747eded918f85107.

The assembler checks in extend-syntax.c simply needed adjusting for
32-bit pointers.

It appears the subsp.c test has never passed on ILP32 due to a missed
optimisation there. Since this isn't a code quality regression, disable
that check on ILP32.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/extend-syntax.c: Fix assembler checks for
	ilp32, disable check-function-bodies on ilp32.
	* gcc.target/aarch64/subsp.c: Only check second scan-assembler
	on lp64 since the code on ilp32 is missing the optimization
	needed for this test to pass.