soong: add sdclang

Change-Id: Ib2b955f76ed15934b11fa2f7b58cf71ea772077a
diff --git a/build/soong/android/variable.go b/build/soong/android/variable.go
index d2f2e5b..b83e953 100644
--- a/build/soong/android/variable.go
+++ b/build/soong/android/variable.go
@@ -15,4 +15,5 @@
 	Healthd_use_battery_info  *bool `json:",omitempty"`
 	TargetNeedsHWCOnFirstRef  *bool `json:",omitempty"`
 	Uses_metadata_as_fde_key  *bool `json:",omitempty"`
+	Target_use_sdclang        *bool `json:",omitempty"`
 }