BLD: enable building NumPy with Meson

This enables building with NumPy on Linux and macOS. Windows support
should be complete to, but is untested as of now and may need a few
tweaks. This contains:
- A set of `meson.build` files and related code generation script
  tweaks, header templates, etc.
- One CI job on Linux
- Basic docs on using Meson to build NumPy (not yet integrated in the
  html docs, it's too early for that - this is for early adopters right
  now).

The build should be complete, with the major exception of SIMD support.
The full test suite passes. See gh-22546 for the tracking issue with
detailed notes on the plan for switching NumPy to Meson as its build
system.

Co-authored-by: Stefan van der Walt <stefanv@berkeley.edu>

1 files changed, 19 insertions, 0 deletions

diff --git a/dev.py b/dev.py
new file mode 100755
index 000000000..205014938
--- /dev/null
+++ b/dev.py
@@ -0,0 +1,19 @@
+#!/usr/bin/env python
+#
+# Example stub for running `python -m dev.py`
+#
+# Copy this into your project root.
+
+import os
+import sys
+import runpy
+
+sys.path.remove(os.path.abspath(os.path.dirname(sys.argv[0])))
+try:
+    runpy.run_module("devpy", run_name="__main__")
+except ImportError:
+    print("Cannot import devpy; please install it using")
+    print()
+    print("  pip install git+https://github.com/scientific-python/devpy")
+    print()
+    sys.exit(1)