Skip optional_mthumb tests if GCC has a default mode

Skip optional_mthumb tests if GCC has a default mode

2017-01-20  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/testsuite/
    * lib/target-supports.exp (check_configured_with): New procedure.
    (check_effective_target_default_mode): new effective target.
    * gcc.target/arm/optional_thumb-1.c: Skip if GCC was configured with a
    default mode.  Fix dg-skip-if target selector syntax.
    * gcc.target/arm/optional_thumb-2.c: Likewise.
    * gcc.target/arm/optional_thumb-3.c: Fix dg-skip-if target selector
    syntax.

From-SVN: r244723