Mantaflow [Part 1]: Added preprocessed Mantaflow source files

Includes preprocessed Mantaflow source files for both OpenMP and TBB (if OpenMP is not present, TBB files will be used instead).

These files come directly from the Mantaflow repository. Future updates to the core fluid solver will take place by updating the files.

Reviewed By: sergey, mont29

Maniphest Tasks: T59995

Differential Revision: https://developer.blender.org/D3850

extern/mantaflow/preprocessed/python/defines.py.reg.cpp

@@ -0,0 +1,24 @@
+#include "registry.h"
+static const Pb::Register _reg(
+    "python/defines.py",
+    "################################################################################\n#\n# "
+    "MantaFlow fluid solver framework\n# Copyright 2011 Tobias Pfaff, Nils Thuerey \n#\n# This "
+    "program is free software, distributed under the terms of the\n# Apache License, Version 2.0 "
+    "\n# http://www.apache.org/licenses/LICENSE-2.0\n#\n# Defines some constants for use in "
+    "python "
+    "subprograms\n#\n#############################################################################"
+    "####\n\n# mantaflow conventions\nReal = float\n\n# some defines to make C code and scripts "
+    "more alike...\nfalse = False\ntrue  = True\nVec3  = vec3\nVec4  = vec4\nVec3Grid = "
+    "VecGrid\n\n# grid flags\nFlagFluid    = 1\nFlagObstacle = 2\nFlagEmpty    = 4\nFlagInflow   "
+    "= 8\nFlagOutflow  = 16\nFlagStick    = 64\nFlagReserved = 256\n# and same for "
+    "FlagGrid::CellType enum names:\nTypeFluid    = 1\nTypeObstacle = 2\nTypeEmpty    = "
+    "4\nTypeInflow   = 8\nTypeOutflow  = 16\nTypeStick    = 64\nTypeReserved = 256\n\n# "
+    "integration mode\nIntEuler = 0\nIntRK2   = 1\nIntRK4   = 2\n\n# CG preconditioner\nPcNone    "
+    "  = 0\nPcMIC       = 1\nPcMGDynamic = 2\nPcMGStatic  = 3\n\n# particles\nPtypeSpray   = "
+    "2\nPtypeBubble  = 4\nPtypeFoam    = 8\nPtypeTracer  = 16\n\n\n\n\n");
+extern "C" {
+void PbRegister_file_0()
+{
+  KEEP_UNUSED(_reg);
+}
+}