Use musl build of n2

We're seeing bugs on the build server only, and previous similar bugs
were caused by issues in the older version of glibc the build server
uses, so try using the musl build of n2 to see if it resolves the
issues.

Bug: 318434287
Test: Presubmits
Change-Id: I416cd77f4dfb4ca04f6dd5b36fa73585a2904b55

ui/build/config.go

@@ -1617,6 +1617,12 @@ func (c *configImpl) NinjaBin() string {
 	return c.PrebuiltBuildTool(binName)
 }
 
+func (c *configImpl) N2Bin() string {
+	path := c.PrebuiltBuildTool("n2")
+	// Use musl instead of glibc because glibc on the build server is old and has bugs
+	return strings.ReplaceAll(path, "/linux-x86/", "/linux_musl-x86/")
+}
+
 func (c *configImpl) PrebuiltBuildTool(name string) string {
 	if v, ok := c.environ.Get("SANITIZE_HOST"); ok {
 		if sanitize := strings.Fields(v); inList("address", sanitize) {

ui/build/ninja.go

@@ -57,7 +57,7 @@ func runNinjaForBuild(ctx Context, config Config) {
 		"--frontend_file", fifo,
 	}
 	if config.useN2 {
-		executable = config.PrebuiltBuildTool("n2")
+		executable = config.N2Bin()
 		args = []string{
 			"-d", "trace",
 			// TODO: implement these features, or remove them.

ui/build/soong.go

@@ -663,7 +663,7 @@ func runSoong(ctx Context, config Config) {
 		ninjaArgs = append(ninjaArgs, targets...)
 		ninjaCmd := config.NinjaBin()
 		if config.useN2 {
-			ninjaCmd = config.PrebuiltBuildTool("n2")
+			ninjaCmd = config.N2Bin()
 		}
 
 		cmd := Command(ctx, config, "soong bootstrap",