Merge pull request #321 from dscho/etc-profile-for-arm64

Start support for MSYSTEM=ARM64

Author: dscho

git-extra/git-extra.install.in

@@ -230,6 +230,32 @@ test -d "$TMPDIR" || test ! -d "$TMP" || {\
 	#
 	# As we no longer need it, delete it.
 	test ! -h /ssl || rm /ssl
+
+	# Allow an i686 version of Git for Windows, augmented by `/arm64/*`, to serve
+	# as sort of an ARM64 version of Git for Windows (because Windows/ARM64 can run
+	# i686 executables via a built-in emulator).
+	test i686 != "$arch" ||
+	grep -q '^ARM64)$' /etc/profile ||
+	sed -i '/^MINGW64)/{
+		# read entire `case` arm until `;;`
+		:1;N;/[^;]$/b1;
+
+		# print out the MINGW64 `case` arm unchanged
+		p;
+
+		# now, transmogrify it into the ARM64 `case` arm:
+		s|^MINGW|ARM|;
+		# change the MINGW_PREFIX
+		s|\${MINGW_PREFIX}|/arm64|;
+		# add the /mingw32/bin fall-back to the PATH
+		s| PATH=[^:]*|&:/mingw32/bin|;
+		# adjust the pkgconfig path
+		s|/share/pkgconfig|&:/mingw32/lib/pkgconfig:/mingw32/share/pkgconfig|;
+		# adjust autoconf path
+		s|:/usr/share/aclocal|:/mingw32/share/aclocal&|;
+		# add the /mingw32 fall-back paths to MANPATH
+		s|:\${MANPATH}|:/mingw32/local/man:/mingw32/share/man&|
+	}' /etc/profile
 }
 
 post_upgrade () {