[ARM] Consistently check for neon in vect effective targets

[ARM] Consistently check for neon in vect effective targets

Conditions checked for ARM targets in vector-related effective targets
are inconsistent:

* sometimes arm*-*-* is checked
* sometimes Neon is checked
* sometimes arm_neon_ok and sometimes arm_neon is used for neon check
* sometimes check_effective_target_* is used, sometimes
* is-effective-target

This patch consolidate all of these check into using is-effective-target
arm_neon and when little endian was checked, the check is kept.

2017-06-28  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/testsuite/
    * lib/target-supports.exp (check_effective_target_vect_int): Replace
    current ARM check by ARM NEON's availability check.
    (check_effective_target_vect_intfloat_cvt): Likewise.
    (check_effective_target_vect_uintfloat_cvt): Likewise.
    (check_effective_target_vect_floatint_cvt): Likewise.
    (check_effective_target_vect_floatuint_cvt): Likewise.
    (check_effective_target_vect_shift): Likewise.
    (check_effective_target_whole_vector_shift): Likewise.
    (check_effective_target_vect_bswap): Likewise.
    (check_effective_target_vect_shift_char): Likewise.
    (check_effective_target_vect_long): Likewise.
    (check_effective_target_vect_float): Likewise.
    (check_effective_target_vect_perm): Likewise.
    (check_effective_target_vect_perm_byte): Likewise.
    (check_effective_target_vect_perm_short): Likewise.
    (check_effective_target_vect_widen_sum_hi_to_si_pattern): Likewise.
    (check_effective_target_vect_widen_sum_qi_to_hi): Likewise.
    (check_effective_target_vect_widen_mult_qi_to_hi): Likewise.
    (check_effective_target_vect_widen_mult_hi_to_si): Likewise.
    (check_effective_target_vect_widen_mult_qi_to_hi_pattern): Likewise.
    (check_effective_target_vect_widen_mult_hi_to_si_pattern): Likewise.
    (check_effective_target_vect_widen_shift): Likewise.
    (check_effective_target_vect_extract_even_odd): Likewise.
    (check_effective_target_vect_interleave): Likewise.
    (check_effective_target_vect_multiple_sizes): Likewise.
    (check_effective_target_vect64): Likewise.
    (check_effective_target_vect_max_reduc): Likewise.

From-SVN: r249744