compiler: add large aggregate IR tests

Add compiler coverage for large aggregate parameters and results,
including function values, interfaces, maps, channels, selects, deferred
calls, goroutines, phis, and multiple results.

compiler/testdata/large.go

@@ -0,0 +1,120 @@
+package main
+
+type largeValue [1025]byte
+
+type largeStruct struct {
+	value [1025]byte
+	ptr   *byte
+}
+
+type largeInterface interface {
+	makeLargeValue() largeValue
+	readLargeValue(largeValue) byte
+}
+
+type largeReceiver largeValue
+
+func makeLargeValue(value byte) largeValue {
+	var result largeValue
+	result[len(result)-1] = value
+	return result
+}
+
+func makeZeroLargeValue() largeValue {
+	return largeValue{}
+}
+
+func passZeroLargeValue() byte {
+	return readLargeValue(largeValue{})
+}
+
+func readLargeValue(value largeValue) byte {
+	return value[len(value)-1]
+}
+
+func useLargeValue() byte {
+	return readLargeValue(makeLargeValue(42))
+}
+
+func useLargeFunctionValue(fn func(largeValue) byte) byte {
+	return fn(makeLargeValue(42))
+}
+
+func (receiver largeReceiver) makeLargeValue() largeValue {
+	return largeValue(receiver)
+}
+
+func (receiver largeReceiver) readLargeValue(value largeValue) byte {
+	return value[len(value)-1]
+}
+
+func useLargeInterface(value largeInterface) byte {
+	return value.readLargeValue(value.makeLargeValue())
+}
+
+func deferLargeValue(value largeValue) {
+	defer readLargeValue(value)
+}
+
+func goLargeValue(value largeValue) {
+	go readLargeValue(value)
+}
+
+func makeLargeResults(value byte) (largeValue, byte) {
+	return makeLargeValue(value), value
+}
+
+func makeTwoLargeResults(value byte) (largeValue, largeValue) {
+	return makeLargeValue(value), makeLargeValue(value + 1)
+}
+
+func makeMixedLargeResults(value byte) (largeValue, byte, largeValue) {
+	return makeLargeValue(value), value + 1, makeLargeValue(value + 2)
+}
+
+func chooseLargeValue(flag bool) largeValue {
+	value := makeLargeValue(1)
+	if flag {
+		value = makeLargeValue(42)
+	}
+	return value
+}
+
+func makePointerLargeValue(value *byte) largeStruct {
+	return largeStruct{ptr: value}
+}
+
+func assertLargeValue(value any) byte {
+	large, ok := value.(largeValue)
+	if !ok {
+		return 0
+	}
+	return large[len(large)-1]
+}
+
+func useLargeMap(key, value largeValue) byte {
+	values := map[largeValue]largeValue{key: value}
+	result, ok := values[key]
+	if !ok {
+		return 0
+	}
+	return result[len(result)-1]
+}
+
+func useLargeChannel(ch chan largeValue, value largeValue) byte {
+	ch <- value
+	result, ok := <-ch
+	if !ok {
+		return 0
+	}
+	return result[len(result)-1]
+}
+
+func selectLargeChannel(ch chan largeValue, value largeValue) byte {
+	select {
+	case ch <- value:
+		return 0
+	case result := <-ch:
+		return result[len(result)-1]
+	}
+}