Remove the shebang from gen_dispatch.py

Instead of having Meson determine the invocator through the shebang
line we explicitly pass the script file to the Python interpreter.

This will allow us to either use Python3 or Python2, or whatever
Python.exe is available on Windows.

include/epoxy/meson.build

@@ -6,6 +6,7 @@ gl_generated = custom_target('gl_generated.h',
                                'gl_generated.h',
                              ],
                              command: [
+                               python,
                                gen_dispatch_py,
                                '--header',
                                '--no-source',
@@ -25,6 +26,7 @@ if build_egl
                                   'egl_generated.h',
                                 ],
                                 command: [
+                                  python,
                                   gen_dispatch_py,
                                   '--header',
                                   '--no-source',
@@ -44,6 +46,7 @@ if build_glx
                                   'glx_generated.h',
                                 ],
                                 command: [
+                                  python,
                                   gen_dispatch_py,
                                   '--header',
                                   '--no-source',
@@ -63,6 +66,7 @@ if build_wgl
                                   'wgl_generated.h',
                                 ],
                                 command: [
+                                  python,
                                   gen_dispatch_py,
                                   '--header',
                                   '--no-source',

meson.build

@@ -202,8 +202,11 @@ configure_file(input: 'epoxy.pc.in',
                install: true,
                install_dir: join_paths(epoxy_libdir, 'pkgconfig'))
 
+# Python
+python = find_program('python', required: true)
+
 # Generates the dispatch tables
-gen_dispatch_py = find_program('src/gen_dispatch.py')
+gen_dispatch_py = join_paths(meson.source_root(), 'src/gen_dispatch.py')
 
 gl_registry = files('registry/gl.xml')
 egl_registry = files('registry/egl.xml')

src/gen_dispatch.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 # Copyright © 2013 Intel Corporation

src/meson.build

@@ -12,6 +12,7 @@ gl_generated = custom_target('gl_generated_dispatch.c',
                                'gl_generated_dispatch.c',
                              ],
                              command: [
+                               python,
                                gen_dispatch_py,
                                '--source',
                                '--no-header',
@@ -29,6 +30,7 @@ if build_egl
                                   'egl_generated_dispatch.c',
                                 ],
                                 command: [
+                                  python,
                                   gen_dispatch_py,
                                   '--source',
                                   '--no-header',
@@ -46,6 +48,7 @@ if build_glx
                                   'glx_generated_dispatch.c',
                                 ],
                                 command: [
+                                  python,
                                   gen_dispatch_py,
                                   '--source',
                                   '--no-header',
@@ -63,6 +66,7 @@ if build_wgl
                                   'wgl_generated_dispatch.c',
                                 ],
                                 command: [
+                                  python,
                                   gen_dispatch_py,
                                   '--source',
                                   '--no-header',