Add meson build system support

[brainos233]

To integrate meson build system, a cross-file is required, the easiest way to do this is to use meson's env2mfile command, which eliminates the need to generate a cross-file manually.

env2mfile requires meson 0.62.0, but Ubuntu 22.04's meson version is 0.61.2, so using pip to install the latest version of meson

For maintaining each platform and architecture, the following variables need to be set to generate the cross-file:

• meson_cross_system: https://mesonbuild.com/Reference-tables.html#operating-system-names
• meson_cross_subsystem: Not needed, if not set, will be set as meson_cross_system, https://mesonbuild.com/Reference-tables.html#subsystem-names-since-120
• meson_cross_kernel: https://mesonbuild.com/Reference-tables.html#kernel-names-since-120
• meson_cross_cpu_family: https://mesonbuild.com/Reference-tables.html#cpu-families
• meson_cross_cpu: There is no reference for, so it has to manually find the appropriate value

Requires meson 1.4.1 because there is a bug before this version, which made not able to use meson's -Dc_std, -Dcpp_std to set c/cxx default standard version.

[brainos233]

#135 is the test case for this pr, here's the example for adding meson package:

from renpybuild.context import Context
from renpybuild.task import task, annotator

version = "package_version"


@task(platforms="all")
def unpack(c: Context):
    c.clean()

    c.var("version", version)
    c.run("tar xf {{source}}/package_name-{{version}}.tar.gz")


@task(platforms="all")
def build(c: Context):
    c.var("version", version)
    c.chdir("package_name-{{version}}")

    c.run("""
        {{ meson_configure }} {{ meson_args }}
        --prefix={{install}}
        --default-library={shared,static,both}
        -D{package_specific_options}
        {build_dir}
        """)

    c.run("{{ meson_compile }} -C {build_dir}")

    c.run("meson install -C {build_dir}")

[renpytom]

Why would we want meson support?

[renpytom]

Ah, never mind - saw the second comment. Let me think about this one, as I don't know if there's enough software using meson to be worth it. (Compared to using an older version of fribidi, a low dependency library.)

[brainos233]

Ah, never mind - saw the second comment. Let me think about this one, as I don't know if there's enough software using meson to be worth it. (Compared to using an older version of fribidi, a low dependency library.)

#136 is the main reason for adding meson build system support, but some of the packages used by renpy have gradually switched to meson, such as freetype2 (experimental) and harfbuzz (official).