aarch64: add -fno-stack-protector to some tests [PR108411]

As discussed in the PR, these recently added tests fail when the
testsuite is executed with -fstack-protector-strong.  To avoid this,
this patch adds -fno-stack-protector to dg-options.

	PR target/108411
	gcc/testsuite
	* g++.target/aarch64/bitfield-abi-warning-align16-O2-extra.C: Add
	-fno-stack-protector.
	* g++.target/aarch64/bitfield-abi-warning-align16-O2.C: Likewise.
	* g++.target/aarch64/bitfield-abi-warning-align32-O2-extra.C: Likewise.
	* g++.target/aarch64/bitfield-abi-warning-align32-O2.C: Likewise.
	* g++.target/aarch64/bitfield-abi-warning-align8-O2.C: Likewise.
	* gcc.target/aarch64/bitfield-abi-warning-align16-O2-extra.c: Likewise.
	* gcc.target/aarch64/bitfield-abi-warning-align16-O2.c: Likewise.
	* gcc.target/aarch64/bitfield-abi-warning-align32-O2-extra.c: Likewise.
	* gcc.target/aarch64/bitfield-abi-warning-align32-O2.c: Likewise.
	* gcc.target/aarch64/bitfield-abi-warning-align8-O2.c: Likewise.