Add 'engine/' from commit 'a8e37fc010'

git-subtree-dir: engine
git-subtree-mainline: b74841629e
git-subtree-split: a8e37fc010

engine/modules/gdscript/tests/scripts/parser/warnings/unassigned_variable.gd

@@ -0,0 +1,11 @@
+func test():
+	var unassigned
+	print(unassigned)
+	unassigned = "something" # Assigned only after use.
+
+	var a
+	print(a) # Unassigned, warn.
+	if a: # Still unassigned, warn.
+		a = 1
+		print(a) # Assigned (dead code), don't warn.
+	print(a) # "Maybe" assigned, don't warn.