transform: run OptimizeMaps during package optimizations

This shrinks transform.Optimize() a little bit, working towards the goal
of tinygo-org#2870. I ran the smoke
tests and there is no practical downside: one test got smaller (??) and
one had a different .hex hash, but other than that there was no
difference.

This should also make TinyGo a liiitle bit faster but it's probably not
even measurable.

transform/optimizer.go

@@ -37,6 +37,11 @@ func OptimizePackage(mod llvm.Module, config *compileopts.Config) {
 		funcPasses.RunFunc(fn)
 	}
 	funcPasses.FinalizeFunc()
+
+	// Run TinyGo-specific optimization passes.
+	if optLevel > 0 {
+		OptimizeMaps(mod)
+	}
 }
 
 // Optimize runs a number of optimization and transformation passes over the
@@ -92,7 +97,6 @@ func Optimize(mod llvm.Module, config *compileopts.Config, optLevel, sizeLevel i
 		goPasses.Run(mod)
 
 		// Run TinyGo-specific optimization passes.
-		OptimizeMaps(mod)
 		OptimizeStringToBytes(mod)
 		OptimizeReflectImplements(mod)
 		OptimizeAllocs(mod, nil, nil)