[amtk/nmake.improvements: 2/2] Visual Studio builds: Support ARM64 Windows builds

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

commit 00393694f437c7e5eab489089a73d8908078c6d8
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue Jul 14 14:52:20 2020 +0800

    Visual Studio builds: Support ARM64 Windows builds
    
    This adds build support for Visual Studio builds to build ARM64 Windows
    binaries, which can either be done on a normal x86/x86-64 Windows machine, or
    directly on an ARM64 Windows machine, provided that the Visual Studio ARM64
    (cross-)compiler is installed and activated.
    
    Note that at this point there is no support for building introspection files as
    there are currently no official Python ARM64 Windows binaries, which is needed
    to build GObject-Introspection.

 win32/detectenv-msvc.mak | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/win32/detectenv-msvc.mak b/win32/detectenv-msvc.mak
index 8201699..a67349b 100644
--- a/win32/detectenv-msvc.mak
+++ b/win32/detectenv-msvc.mak
@@ -21,6 +21,8 @@ _HASH=^#
     && ![echo PLAT=Win32 >> vercl.x] \
     && ![echo $(_HASH)elif defined(_M_AMD64) >> vercl.x] \
     && ![echo PLAT=x64 >> vercl.x] \
+    && ![echo $(_HASH)elif defined(_M_ARM64) >> vercl.x] \
+    && ![echo PLAT=arm64 >> vercl.x] \
     && ![echo $(_HASH)endif >> vercl.x] \
     && ![cl -nologo -TC -P vercl.x $(ERRNUL)]
 !include vercl.i
@@ -84,6 +86,8 @@ CFLAGS_BASE = $(CFLAGS_BASE) /d2Zi+
 
 !if "$(PLAT)" == "x64"
 LDFLAGS_ARCH = /machine:x64
+!elseif "$(PLAT)" == "arm64"
+LDFLAGS_ARCH = /machine:arm64
 !else
 LDFLAGS_ARCH = /machine:x86
 !endif