Add support for building NDK modules.

Change-Id: I2c5ede530e40a635e26ae45950580ef450e7dcc6
diff --git a/cc/arm64_device.go b/cc/arm64_device.go
index ac0d94a..309d01d 100644
--- a/cc/arm64_device.go
+++ b/cc/arm64_device.go
@@ -88,6 +88,10 @@
 
 var toolchainArm64Singleton = &toolchainArm64{}
 
+func (t *toolchainArm64) Name() string {
+	return "arm64"
+}
+
 func (t *toolchainArm64) GccRoot() string {
 	return "${arm64GccRoot}"
 }
@@ -96,6 +100,10 @@
 	return "${arm64GccTriple}"
 }
 
+func (t *toolchainArm64) GccVersion() string {
+	return "${arm64GccVersion}"
+}
+
 func (t *toolchainArm64) Cflags() string {
 	return "${arm64Cflags} ${arm64IncludeFlags}"
 }