Optimizer - Started work on function inlining

For now:
* Option that triggers inlining
* Compute list of inline-able functions

test/build.srd

@@ -9,6 +9,7 @@
 		)
 		(constant-propagation on)
 		(dead-code-elimination on)
+		(function-inlining on)
 	)
 )
 

test/demo.srd

@@ -362,9 +362,9 @@
 
 (fn bloom-downsample (target level)
 	(locals m w h)
-	(set m (inv (pow 2 $level)))
-	(set w (mul $vp-width $m))
-	(set h (mul $vp-height $m))
+	(set m (pow 2 $level))
+	(set w (div $vp-width $m))
+	(set h (div $vp-height $m))
 
 	(use-pipeline pl-bloom-downsample)
 	(use-framebuffer target)