c++ 20 fixes

[cyrush]

vtkm hacks:
            filter_file(r"\>whichRound", ">WhichRound", "vtkm/filter/scalar_topology/worklet/contourtree_distributed/HierarchicalContourTree.h")

            filter_file(r"NRounds", "NumRounds", "vtkm/filter/scalar_topology/worklet/contourtree_distributed/HierarchicalContourTree.h")

            filter_file(r"CellFacePortal", "CellEdgesPortal", "vtkm/filter/contour/worklet/mir/MIRTables.h")

        if self.cxx_std == "20":

            filter_file(r"std::memory_order::", "std::", "vtkm/cont/internal/DeviceAdapterMemoryManager.cxx")

            filter_file(r"HierarchicalHyperSweeper<SweepValueType, ContourTreeFieldType>\(", "HierarchicalHyperSweeper(", "vtkm/filter/scalar_topology/worklet/contourtree_distributed/HierarchicalHyperSweeper.h")

            filter_file(r"TreeGrafter<MeshType, FieldType>\(", "TreeGrafter(", "vtkm/filter/scalar_topology/worklet/contourtree_distributed/TreeGrafter.h")

Ascent:              my_flags.append("-Wno-missing-template-arg-list-after-template-kw")

[cyrush]

More build tweaks for mi300a:

vtkm:  
+        if name == "cxxflags" and "+rocm" in self.spec:

+            my_flags.append("-fgpu-rdc -DDESUL_ATOMICS_ENABLE_HIP=ON -DDESUL_ATOMICS_ENABLE_HIP_SEPARABLE_COMPILATION=ON")

 |
and kokkos:
+            options.append(self.define("Kokkos_ARCH_AMD_GFX942", "ON"))

+            options.append(self.define("Kokkos_ENABLE_HIP_RELOCATABLE_DEVICE_CODE", "ON"))

 
and ascent:
+                cmake_args.append("-DHIP_HIPCC_FLAGS=%s --rocm-path=%s -fgpu-rdc --offload-arch=gfx942" % (env.get("CXXFLAGS", "-std=c++%s -O2" % self.cxx_std), env.get("ROCM_PATH", "/opt/rocm-6.4.0"))) # "/usr/tce/packages/rocm/rocm-6.4.0beta1")))

[cyrush]

spack-stage-vtkm-2.2.0-mwcgpzbq6ml3bqcitkpszcl4j5ogt555/spack-src/vtkm/Bounds.h:270:25: warning: overlapping comparisons always evaluate to true [-Wtautological-overlap-compare]
(void)((component >= 0) || (component < 3));
       ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~

[cyrush]

Note: A few of these are due to vtk-m 2.2 and may not apply