GH-114809: Add support for macOS multi-arch builds with the JIT enabled (#131751)

Co-authored-by: Ronald Oussoren <ronaldoussoren@mac.com>
Co-authored-by: Brandt Bucher <brandtbucher@microsoft.com>

Tools/jit/build.py

@@ -11,7 +11,10 @@ if __name__ == "__main__":
     comment = f"$ {shlex.join([pathlib.Path(sys.executable).name] + sys.argv)}"
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument(
-        "target", type=_targets.get_target, help="a PEP 11 target triple to compile for"
+        "target",
+        nargs="+",
+        type=_targets.get_target,
+        help="a PEP 11 target triple to compile for",
     )
     parser.add_argument(
         "-d", "--debug", action="store_true", help="compile for a debug build of Python"
@@ -23,6 +26,22 @@ if __name__ == "__main__":
         "-v", "--verbose", action="store_true", help="echo commands as they are run"
     )
     args = parser.parse_args()
-    args.target.debug = args.debug
-    args.target.verbose = args.verbose
-    args.target.build(pathlib.Path.cwd(), comment=comment, force=args.force)
+    for target in args.target:
+        target.debug = args.debug
+        target.force = args.force
+        target.verbose = args.verbose
+        target.build(
+            pathlib.Path.cwd(),
+            comment=comment,
+            stencils_h=f"jit_stencils-{target.triple}.h",
+            force=args.force,
+        )
+
+    with open("jit_stencils.h", "w") as fp:
+        for idx, target in enumerate(args.target):
+            fp.write(f"#{'if' if idx == 0 else 'elif'} {target.condition}\n")
+            fp.write(f'#include "jit_stencils-{target.triple}.h"\n')
+
+        fp.write("#else\n")
+        fp.write('#error "unexpected target"\n')
+        fp.write("#endif\n")