[gtk/gtk-3-24] win32/gtk-introspection-msvc.mak: Prepare for ARM64 builds

[Chun-wei Fan <fanchunwei src gnome org>]

commit c3b9f5612112d2fad577587b32d75f8ab6d86a8f
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue Feb 23 17:36:42 2021 +0800

    win32/gtk-introspection-msvc.mak: Prepare for ARM64 builds
    
    Currently, introspection is not well-supported for ARM64 Windows builds as:
    
    * There is no official Python release for ARM64 Windows, but it is currently
      possible to build it with sufficient support for G-I, however...
    
    * The tooling in Python still needs to be updated to enable ARM64 Windows
      builds for use with g-ir-scanner and friends, and...
    
    * Introspection builds must be done on an ARM64 system, since we are running a
      dumper binary to generate the .gir files
    
    This will attempt to prepare things for building GTK's introspection files on
    Windows ARM64, but will require a custom installation of Python as noted above,
    for the time being

 win32/gtk-introspection-msvc.mak | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/win32/gtk-introspection-msvc.mak b/win32/gtk-introspection-msvc.mak
index aee0dfccbe..d2af90b5cb 100644
--- a/win32/gtk-introspection-msvc.mak
+++ b/win32/gtk-introspection-msvc.mak
@@ -22,6 +22,8 @@ built_install_typelibs =      \
 
 !if "$(PLAT)" == "x64"
 AT_PLAT=x86_64
+!elseif "$(PLAT)" == "arm64"
+AT_PLAT=aarch64
 !else
 AT_PLAT=i686
 !endif