[Flang][OpenMP] NFC: Move OpenMP parser tests to a sub-directory

Now that the test files are in the OpenMP subdirectory, remove the
`omp` prefix.

diff --git a/flang/test/Parser/omp-allocate-unparse.f90 b/flang/test/Parser/OpenMP/allocate-unparse.f90
similarity index 100%
rename from flang/test/Parser/omp-allocate-unparse.f90
rename to flang/test/Parser/OpenMP/allocate-unparse.f90

diff --git a/flang/test/Parser/omp-atomic-unparse.f90 b/flang/test/Parser/OpenMP/atomic-unparse.f90
similarity index 100%
rename from flang/test/Parser/omp-atomic-unparse.f90
rename to flang/test/Parser/OpenMP/atomic-unparse.f90

diff --git a/flang/test/Parser/omp-declare_target-device_type.f90 b/flang/test/Parser/OpenMP/declare_target-device_type.f90
similarity index 100%
rename from flang/test/Parser/omp-declare_target-device_type.f90
rename to flang/test/Parser/OpenMP/declare_target-device_type.f90

diff --git a/flang/test/Parser/omp-defaultmap-unparse.f90 b/flang/test/Parser/OpenMP/defaultmap-unparse.f90
similarity index 100%
rename from flang/test/Parser/omp-defaultmap-unparse.f90
rename to flang/test/Parser/OpenMP/defaultmap-unparse.f90

diff --git a/flang/test/Parser/omp-in-reduction-clause.f90 b/flang/test/Parser/OpenMP/in-reduction-clause.f90
similarity index 100%
rename from flang/test/Parser/omp-in-reduction-clause.f90
rename to flang/test/Parser/OpenMP/in-reduction-clause.f90

diff --git a/flang/test/Parser/omp-nontemporal-unparse.f90 b/flang/test/Parser/OpenMP/nontemporal-unparse.f90
similarity index 100%
rename from flang/test/Parser/omp-nontemporal-unparse.f90
rename to flang/test/Parser/OpenMP/nontemporal-unparse.f90

diff --git a/flang/test/Parser/omp-order-clause01.f90 b/flang/test/Parser/OpenMP/order-clause01.f90
similarity index 100%
rename from flang/test/Parser/omp-order-clause01.f90
rename to flang/test/Parser/OpenMP/order-clause01.f90

diff --git a/flang/test/Parser/omp-sections.f90 b/flang/test/Parser/OpenMP/sections.f90
similarity index 100%
rename from flang/test/Parser/omp-sections.f90
rename to flang/test/Parser/OpenMP/sections.f90

diff --git a/flang/test/Parser/omp_target_device_parse.f90 b/flang/test/Parser/OpenMP/target_device_parse.f90
similarity index 100%
rename from flang/test/Parser/omp_target_device_parse.f90
rename to flang/test/Parser/OpenMP/target_device_parse.f90

diff --git a/flang/test/Parser/omp_target_device_unparse.f90 b/flang/test/Parser/OpenMP/target_device_unparse.f90
similarity index 100%
rename from flang/test/Parser/omp_target_device_unparse.f90
rename to flang/test/Parser/OpenMP/target_device_unparse.f90

diff --git a/flang/test/Parser/omp-tile-size.f90 b/flang/test/Parser/OpenMP/tile-size.f90
similarity index 100%
rename from flang/test/Parser/omp-tile-size.f90
rename to flang/test/Parser/OpenMP/tile-size.f90

diff --git a/flang/test/Parser/omp-tile.f90 b/flang/test/Parser/OpenMP/tile.f90
similarity index 100%
rename from flang/test/Parser/omp-tile.f90
rename to flang/test/Parser/OpenMP/tile.f90

diff --git a/flang/test/Parser/omp-unroll-full.f90 b/flang/test/Parser/OpenMP/unroll-full.f90
similarity index 100%
rename from flang/test/Parser/omp-unroll-full.f90
rename to flang/test/Parser/OpenMP/unroll-full.f90

diff --git a/flang/test/Parser/omp-unroll.f90 b/flang/test/Parser/OpenMP/unroll.f90
similarity index 100%
rename from flang/test/Parser/omp-unroll.f90
rename to flang/test/Parser/OpenMP/unroll.f90