Move coroutine passes from Makefile to compiler itself

This is much more convenient.

compiler.go

@@ -1746,8 +1746,12 @@ func (c *Compiler) Optimize(optLevel, sizeLevel int) {
 	builder.PopulateFunc(funcPasses)
 
 	modPasses := llvm.NewPassManager()
+	modPasses.AddCoroEarlyPass()
+	modPasses.AddCoroSplitPass()
+	modPasses.AddCoroElidePass()
 	defer modPasses.Dispose()
 	builder.Populate(modPasses)
+	modPasses.AddCoroCleanupPass()
 
 	modPasses.Run(c.mod)
 }