Remove generator.js from LOCAL_SRC_FILES

The build system does not do anything with .js files in LOCAL_SRC_FILES.
To reduce confusion, and prevent typos, it is becoming a warning to add
unused entries into LOCAL_SRC_FILES.

FPIIM-449

Change-Id: I1f7665cd08767dd3308c12eb796a62eaeed86915
diff --git a/Android.v8common.mk b/Android.v8common.mk
index a8d9bb5..9684e86 100644
--- a/Android.v8common.mk
+++ b/Android.v8common.mk
@@ -126,7 +126,6 @@
 	src/frames.cc \
 	src/full-codegen.cc \
 	src/func-name-inferrer.cc \
-	src/generator.js \
 	src/global-handles.cc \
 	src/handles.cc \
 	src/heap-profiler.cc \