fix main return value issue, use int64 instead of int32

Author: xrdavies

compiler/compiler/compiler.go

@@ -222,7 +222,7 @@ func (c *Compiler) addGlobal() {
 	b.NewRet(nil)
 
 	// main.main function, body will be added later
-	c.mainFunc = c.module.NewFunc("main", types.I32.LLVM())
+	c.mainFunc = c.module.NewFunc("main", types.I64.LLVM()) // TODO: Size based on arch
 	mainBlock := c.mainFunc.NewBlock(name.Block())
 	mainBlock.NewCall(c.initGlobalsFunc)
 }

tests/examples/always-true.cell

@@ -1,3 +1,3 @@
 function main() {
-    return true
+    return 0
 }

tests/examples/helloworld.cell

@@ -7,4 +7,4 @@ function main() {
     ok = tx.ScriptVerify()
     debug.Printf("hello world! %d\n", ok)
     return 0
-}
+}

tests/examples/tx-script-verify.cell

@@ -9,5 +9,5 @@ function main() {
 
 	// 1000
 	debug.Printf("%d\n", ok)
-	return true
-}
+	return 0
+}

tests/examples/types.cell

@@ -14,5 +14,5 @@ function main() {
     r2 := v3 + v4
     debug.Printf(r2)
 
-    return true
+    return 0
 }