Various small build fixes

[carstene1ns]

Still investigating the WiiU problem, but Vita and 3DS work again.

[Ghabry]

what appears to work for Wiiu is passing -Db_staticpic=false as an argument to meson.

Or in meson-cross.txt:

[built-in options]
b_staticpic = false

(maybe also disable it on the other homebrew platforms? Is only useful on our "main" platforms, linux, macOS, Android)

[Ghabry]

Not useful (?) because harfbuzz is disabled on WiiU but this patch fixes the build:

diff -Naur harfbuzz-8.3.0-orig/meson.build harfbuzz-8.3.0/meson.build
--- harfbuzz-8.3.0-orig/meson.build 2024-03-29 23:30:58.396713998 +0100
+++ harfbuzz-8.3.0/meson.build  2024-03-29 23:34:46.996124668 +0100
@@ -331,13 +331,6 @@

 # threads
 thread_dep = null_dep
-if host_machine.system() != 'windows'
-  thread_dep = dependency('threads', required: false)
-
-  if thread_dep.found()
-    conf.set('HAVE_PTHREAD', 1)
-  endif
-endif

 conf.set_quoted('PACKAGE_NAME', 'HarfBuzz')
 conf.set_quoted('PACKAGE_VERSION', meson.project_version())