[OpenMP] Remove help and documentation for old flag

Summary:
The `-fopenmp-target-new-runtime` flag has not been used for awhile. It
was present in a previous release so we shouldn't remove it for
backwards compatibility, but we shouldn't have documentation or a help
message for it.

clang/docs/ClangCommandLineReference.rst

@@ -2093,10 +2093,6 @@ Emit OpenMP code only for SIMD-based constructs.
 
 Enable debugging in the OpenMP offloading device RTL
 
-.. option:: -fopenmp-target-new-runtime, -fno-openmp-target-new-runtime
-
-Use the new bitcode library for OpenMP offloading
-
 .. option:: -fopenmp-offload-mandatory
 
 Indicate that offloading to the device is mandatory and do not generate host-fallback code.

clang/include/clang/Basic/LangOptions.def

@@ -242,7 +242,6 @@ LANGOPT(OpenMPCUDAForceFullRuntime , 1, 0, "Force to use full runtime in all con
 LANGOPT(OpenMPCUDANumSMs  , 32, 0, "Number of SMs for CUDA devices.")
 LANGOPT(OpenMPCUDABlocksPerSM  , 32, 0, "Number of blocks per SM for CUDA devices.")
 LANGOPT(OpenMPCUDAReductionBufNum , 32, 1024, "Number of the reduction records in the intermediate reduction buffer used for the teams reductions.")
-LANGOPT(OpenMPTargetNewRuntime , 1, 0, "Use the new bitcode library for OpenMP offloading")
 LANGOPT(OpenMPTargetDebug , 32, 0, "Enable debugging in the OpenMP offloading device RTL")
 LANGOPT(OpenMPOptimisticCollapse  , 1, 0, "Use at most 32 bits to represent the collapsed loop nest counter.")
 LANGOPT(OpenMPThreadSubscription  , 1, 0, "Assume work-shared loops do not have more iterations than participating threads.")

clang/include/clang/Driver/Options.td

@@ -2504,10 +2504,10 @@ def fopenmp_offload_mandatory : Flag<["-"], "fopenmp-offload-mandatory">, Group<
   Flags<[CC1Option, NoArgumentUnused]>,
   HelpText<"Do not create a host fallback if offloading to the device fails.">,
   MarshallingInfoFlag<LangOpts<"OpenMPOffloadMandatory">>;
-defm openmp_target_new_runtime: BoolFOption<"openmp-target-new-runtime",
-  LangOpts<"OpenMPTargetNewRuntime">, DefaultTrue,
-  PosFlag<SetTrue, [CC1Option], "Use the new bitcode library for OpenMP offloading">,
-  NegFlag<SetFalse>>;
+def fopenmp_target_new_runtime : Flag<["-"], "fopenmp-target-new-runtime">,
+  Group<f_Group>, Flags<[CC1Option, HelpHidden]>;
+def fno_openmp_target_new_runtime : Flag<["-"], "fno-openmp-target-new-runtime">,
+  Group<f_Group>, Flags<[CC1Option, HelpHidden]>;
 defm openmp_optimistic_collapse : BoolFOption<"openmp-optimistic-collapse",
   LangOpts<"OpenMPOptimisticCollapse">, DefaultFalse,
   PosFlag<SetTrue, [CC1Option]>, NegFlag<SetFalse>, BothFlags<[NoArgumentUnused, HelpHidden]>>;