aarch64: Add missing movmisalign patterns

aarch64: Add missing movmisalign patterns

The Advanced SIMD movmisalign patterns didn't handle 16-bit
FP modes, which meant that the vector loop for:

  void
  test (_Float16 *data)
  {
    _Pragma ("omp simd")
    for (int i = 0; i < 8; ++i)
      data[i] = 1.0;
  }

would be versioned for alignment.

This was causing some new failures in aarch64/sve/single_5.c:

FAIL: gcc.target/aarch64/sve/single_5.c scan-assembler-not \\tb
FAIL: gcc.target/aarch64/sve/single_5.c scan-assembler-not \\tcmp
FAIL: gcc.target/aarch64/sve/single_5.c scan-assembler-times \\tstr\\tq[0-9]+, 10

but I didn't look into what changed from earlier releases.
Adding the missing modes removes some existing xfails.

gcc/
	* config/aarch64/aarch64-simd.md (movmisalign<mode>): Extend from
	VALL to VALL_F16.

gcc/testsuite/
	* gcc.target/aarch64/sve/single_5.c: Remove some XFAILs.