[flang] Fix tests

Add an additional flag to tests.

Author: NimishMishra

flang/test/Lower/OpenMP/Todo/task_detach.f90

@@ -1,6 +1,6 @@
 ! REQUIRES: openmp_runtime
-! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
-! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd bbc -emit-fir %openmp_flags -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir %openmp_flags -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
 
 !===============================================================================
 ! `detach` clause

flang/test/Parser/OpenMP/task.f90

@@ -1,6 +1,6 @@
 ! REQUIRES: openmp_runtime
-! RUN: %flang_fc1 -fdebug-dump-parse-tree -fopenmp -fopenmp-version=50  %s | FileCheck --ignore-case %s
-! RUN: %flang_fc1 -fdebug-unparse -fopenmp -fopenmp-version=50  %s | FileCheck --ignore-case --check-prefix="CHECK-UNPARSE" %s
+! RUN: %flang_fc1 %openmp_flags -fdebug-dump-parse-tree -fopenmp -fopenmp-version=50  %s | FileCheck --ignore-case %s
+! RUN: %flang_fc1 %openmp_flags -fdebug-unparse -fopenmp -fopenmp-version=50  %s | FileCheck --ignore-case --check-prefix="CHECK-UNPARSE" %s
 
 !CHECK: OmpBlockDirective -> llvm::omp::Directive = task
 !CHECK: OmpClauseList -> OmpClause -> Detach -> OmpDetachClause -> OmpObject -> Designator -> DataRef -> Name = 'event'