[wpimath] Increase constexpr support in geometry data types (#4231)

This uses std::is_constant_evaluated() to conditionally use the gcem library for constexpr calculations.

upstream_utils/update_gcem.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+
+import os
+import shutil
+
+from upstream_utils import (
+    get_repo_root,
+    clone_repo,
+    comment_out_invalid_includes,
+    walk_cwd_and_copy_if,
+    git_am,
+)
+
+
+def main():
+    upstream_root = clone_repo("https://github.com/kthohr/gcem.git", "v1.16.0")
+    wpilib_root = get_repo_root()
+    wpimath = os.path.join(wpilib_root, "wpimath")
+
+    # Apply patches to upstream Git repo
+    os.chdir(upstream_root)
+    for f in []:
+        git_am(os.path.join(wpilib_root, "upstream_utils/gcem_patches", f))
+
+    # Delete old install
+    for d in [
+        "src/main/native/thirdparty/gcem/include",
+    ]:
+        shutil.rmtree(os.path.join(wpimath, d), ignore_errors=True)
+
+    # Copy gcem include files into allwpilib
+    include_files = walk_cwd_and_copy_if(
+        lambda dp, f: dp.endswith("include")
+        or dp.endswith("gcem_incl")
+        or dp.endswith("quadrature"),
+        os.path.join(wpimath, "src/main/native/thirdparty/gcem"),
+    )
+
+    for f in include_files:
+        comment_out_invalid_includes(
+            f, [os.path.join(wpimath, "src/main/native/thirdparty/gcem/include")]
+        )
+
+
+if __name__ == "__main__":
+    main()