aarch64: More SME vs -mtrack-speculation

aarch64: More SME vs -mtrack-speculation

The sequence to commit a lazy save includes a branch based on
whether TPIDR2_EL0 is zero.  The code assumed that CBZ could
be used for this, but that instruction is forbidden when
-mtrack-speculation is being used.

gcc/
	* config/aarch64/aarch64.cc (aarch64_mode_emit_local_sme_state):
	Use aarch64_gen_compare_zero_and_branch rather than emitting
	a CBZ directly.

gcc/testsuite/
	* gcc.target/aarch64/sme/locally_streaming_1_ts.c: New test.
	* gcc.target/aarch64/sme/sibcall_7_ts.c: Likewise.