meson: mingw do not need _USE_MATH_DEFINES, only MSVC need it

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Eric Engestrom <eric@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37289>

meson.build

@@ -1057,11 +1057,11 @@ elif host_machine.system() == 'windows'
   pre_args += [
     '-D_WINDOWS', '-D_WIN32_WINNT=0x0A00', '-DWINVER=0x0A00',
     '-DPIPE_SUBSYSTEM_WINDOWS_USER',
-    '-D_USE_MATH_DEFINES',  # XXX: scons didn't use this for mingw
   ]
   if cc.get_argument_syntax() == 'msvc'
     pre_args += [
       '-DVC_EXTRALEAN',
+      '-D_USE_MATH_DEFINES',
       '-D_CRT_SECURE_NO_WARNINGS',
       '-D_CRT_SECURE_NO_DEPRECATE',
       '-D_SCL_SECURE_NO_WARNINGS',