installer: add CLANGARM64 support

This replaces our earlier efforts to support ARM64 for Git for Windows.
It uses the new CLANGARM64 MSYSTEM, so ARM64 now becomes a first-class
citizen.

Signed-off-by: Dennis Ameling <dennis@dennisameling.com>

Author: dennisameling

installer/release.sh

@@ -78,13 +78,6 @@ do
 	--include-pdbs)
 		include_pdbs=t
 		;;
-	--include-arm64-artifacts=*)
-		case "${1#*=}" in
-		/*) ;; # absolute path, okay
-		*) die "Need an absolute path: $1";;
-		esac
-		arm64_artifacts_directory="${1#*=}"
-		;;
 	*)
 		break
 	esac
@@ -120,6 +113,11 @@ MINGW64)
 	BITNESS=64
 	ARCH=x86_64
 	;;
+CLANGARM64)
+	BITNESS=64
+	ARCH=aarch64
+	inno_defines="$inno_defines$LF#define INSTALLER_FILENAME_SUFFIX 'arm64'"
+	;;
 *)
 	die "Unhandled MSYSTEM: $MSYSTEM"
 	;;
@@ -317,17 +315,6 @@ test -z "$include_pdbs" || {
 } ||
 die "Could not include .pdb files"
 
-test -z "$arm64_artifacts_directory" || {
-	echo "Including ARM64 artifacts from $arm64_artifacts_directory" &&
-	inno_defines="$inno_defines$LF#define INSTALLER_FILENAME_SUFFIX 'arm64'" &&
-	mixed="$(cygpath -m "$arm64_artifacts_directory")" &&
-	find "$arm64_artifacts_directory" -type f |
-	sed -e "s|^$arm64_artifacts_directory\\(/.*\)\?/\([^/]*\)$|Source: \"$mixed\\1/\\2\"; DestDir: {app}/arm64\\1; Flags: replacesameversion restartreplace; AfterInstall: DeleteFromVirtualStore|" \
-		-e 's|/|\\|g' \
-		>> file-list.iss
-} ||
-die "Could not include ARM64 artifacts"
-
 etc_gitconfig_dir="${etc_gitconfig%/gitconfig}"
 printf "%s\n%s\n%s\n%s\n%s\n%s%s" \
 	"#define APP_VERSION '$displayver'" \