[NFC][Flang] Add simd collapse test case
Flang supports lowering collapse clause to MLIR for worksharing loops
and simd loops. Simd collapse clause is represented in MLIR code as a
simd-loop having a list of indices, bounds and steps where the size of the list
is equal to the collapse value.
Support for simd collapse clause was added by several patches:
https://reviews.llvm.org/D118065 -> basic support for simd-loop in MLIR.
Loop collapsing is done in the same way as
for worksharing loops:
https://reviews.llvm.org/D105706
https://reviews.llvm.org/D125282 -> support for lowering simd clause from
Fortran into MLIR
https://reviews.llvm.org/D125302 -> lowering collapse clause from Fortran to
MLIR. Lowering collapse clause is done
before simd-specific function is called.
https://reviews.llvm.org/D128338 -> modified the MLIR representation of
collapse clause. Removed collapse keyword
in OpenMP MLIR dialect. Use loop list to
represent collapse clause. This loop list
is created by changes from patch:
https://reviews.llvm.org/D125302 and it is
passed to function responsible for lowering
of simd directive which was implemented in
patch: https://reviews.llvm.org/D125282
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D132023
Signed-off-by: Dominik Adamski <dominik.adamski@amd.com>