refactor: move cgoSupported to internal/platform package

Created runtime/internal/lib/internal/platform package to house the
CgoSupported function, following the established pattern used by other
internal packages like internal/itoa.

Changes:
- Created runtime/internal/lib/internal/platform/platform.go
- Moved cgoSupported function to platform.CgoSupported
- Updated runtime/internal/lib/go/build/build.go to import and use
  the new package

This refactoring improves code organization by separating
platform-specific utilities into their own package, making the code
more maintainable and reusable.

🤖 Generated with [codeagent](https://github.com/qbox/codeagent)
Co-authored-by: luoliwoshang <luoliwoshang@users.noreply.github.com>

runtime/internal/lib/go/build/build.go

@@ -14,6 +14,8 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
+
+	"github.com/goplus/llgo/runtime/internal/lib/internal/platform"
 )
 
 // Type aliases to reference standard library types
@@ -77,7 +79,7 @@ func defaultContext() Context {
 		c.CgoEnabled = false
 	default:
 		if runtime.GOARCH == c.GOARCH && runtime.GOOS == c.GOOS {
-			c.CgoEnabled = cgoSupported(c.GOOS, c.GOARCH)
+			c.CgoEnabled = platform.CgoSupported(c.GOOS, c.GOARCH)
 			break
 		}
 		c.CgoEnabled = false
@@ -120,23 +122,3 @@ func buildToolTags() []string {
 		"goexperiment.boringcrypto", // Default boring crypto experiment
 	}
 }
-
-// cgoSupported returns whether CGO is supported for the given GOOS/GOARCH.
-// This is a simplified version of internal/platform.CgoSupported.
-func cgoSupported(goos, goarch string) bool {
-	// Most common platforms support CGO
-	switch goos + "/" + goarch {
-	case "darwin/amd64", "darwin/arm64",
-		"linux/386", "linux/amd64", "linux/arm", "linux/arm64",
-		"windows/386", "windows/amd64", "windows/arm64",
-		"freebsd/386", "freebsd/amd64", "freebsd/arm", "freebsd/arm64",
-		"openbsd/386", "openbsd/amd64", "openbsd/arm", "openbsd/arm64",
-		"netbsd/386", "netbsd/amd64", "netbsd/arm", "netbsd/arm64",
-		"android/386", "android/amd64", "android/arm", "android/arm64",
-		"illumos/amd64",
-		"solaris/amd64",
-		"linux/ppc64le", "linux/riscv64", "linux/s390x":
-		return true
-	}
-	return false
-}

runtime/internal/lib/internal/platform/platform.go

@@ -0,0 +1,29 @@
+// Copyright 2024 The GoPlus Authors (goplus.org). All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package platform provides platform-specific utilities.
+package platform
+
+// llgo:skipall
+type _platform struct{}
+
+// CgoSupported returns whether CGO is supported for the given GOOS/GOARCH.
+// This is a simplified version of internal/platform.CgoSupported.
+func CgoSupported(goos, goarch string) bool {
+	// Most common platforms support CGO
+	switch goos + "/" + goarch {
+	case "darwin/amd64", "darwin/arm64",
+		"linux/386", "linux/amd64", "linux/arm", "linux/arm64",
+		"windows/386", "windows/amd64", "windows/arm64",
+		"freebsd/386", "freebsd/amd64", "freebsd/arm", "freebsd/arm64",
+		"openbsd/386", "openbsd/amd64", "openbsd/arm", "openbsd/arm64",
+		"netbsd/386", "netbsd/amd64", "netbsd/arm", "netbsd/arm64",
+		"android/386", "android/amd64", "android/arm", "android/arm64",
+		"illumos/amd64",
+		"solaris/amd64",
+		"linux/ppc64le", "linux/riscv64", "linux/s390x":
+		return true
+	}
+	return false
+}