Revert "[OpenMP] [test] Don't use the compiler's omp.h in tasking/omp50_taskdep_depobj.c"

This reverts commit b3b3ffd.

Author: mstorsjo

openmp/runtime/test/lit.cfg

@@ -73,6 +73,7 @@ if config.target_arch == "s390x":
     flags += " -mbackchain"
 
 config.test_flags = " -I " + config.omp_header_directory + flags
+config.test_flags_use_compiler_omp_h = flags
 
 
 # extra libraries
@@ -209,6 +210,16 @@ config.substitutions.append(("%libomp-run", "%t"))
 config.substitutions.append(("%clangXX", config.test_cxx_compiler))
 config.substitutions.append(("%clang", config.test_c_compiler))
 config.substitutions.append(("%openmp_flags", config.test_openmp_flags))
+# %flags-use-compiler-omp-h allows us to use the test compiler's omp.h file which
+# may have different definitions of structures than our omp.h file.
+if config.is_standalone_build and config.test_compiler_has_omp_h:
+    config.substitutions.append(("%flags-use-compiler-omp-h",
+        config.test_flags_use_compiler_omp_h))
+else:
+    # If testing the runtime within an LLVM tree, then always include omp.h
+    # directory associated with the new clang compiler.
+    config.substitutions.append(("%flags-use-compiler-omp-h",
+        config.test_flags))
 config.substitutions.append(("%flags", config.test_flags))
 config.substitutions.append(("%python", '"%s"' % (sys.executable)))
 config.substitutions.append(("%not", config.test_not))

openmp/runtime/test/tasking/omp50_taskdep_depobj.c

@@ -1,4 +1,4 @@
-// RUN: %clang %openmp_flags %flags %s -o %t && %libomp-run
+// RUN: %clang %openmp_flags %flags-use-compiler-omp-h %s -o %t && %libomp-run
 // UNSUPPORTED: gcc-5, gcc-6, gcc-7, gcc-8
 // UNSUPPORTED: clang-5, clang-6, clang-7, clang-8, clang-9, clang-10
 // UNSUPPORTED: icc