Support ASAN for ckati and ninja

I missed this when converting to soong_ui.

Test: m -j blueprint_tools (check soong.log)
Test: SANITIZE_HOST=address m -j blueprint_tools
Change-Id: I01eb567db6848dc36dd679557291a4e600a63bba

ui/build/config.go

@@ -318,3 +318,15 @@ func (c *configImpl) HostPrebuiltTag() string {
 		panic("Unsupported OS")
 	}
 }
+
+func (c *configImpl) PrebuiltBuildTool(name string) string {
+	if v, ok := c.environ.Get("SANITIZE_HOST"); ok {
+		if sanitize := strings.Fields(v); inList("address", sanitize) {
+			asan := filepath.Join("prebuilts/build-tools", c.HostPrebuiltTag(), "asan/bin", name)
+			if _, err := os.Stat(asan); err == nil {
+				return asan
+			}
+		}
+	}
+	return filepath.Join("prebuilts/build-tools", c.HostPrebuiltTag(), "bin", name)
+}

ui/build/kati.go

@@ -65,7 +65,7 @@ func runKati(ctx Context, config Config) {
 
 	genKatiSuffix(ctx, config)
 
-	executable := "prebuilts/build-tools/" + config.HostPrebuiltTag() + "/bin/ckati"
+	executable := config.PrebuiltBuildTool("ckati")
 	args := []string{
 		"--ninja",
 		"--ninja_dir=" + config.OutDir(),

ui/build/ninja.go

@@ -26,7 +26,7 @@ func runNinja(ctx Context, config Config) {
 	ctx.BeginTrace("ninja")
 	defer ctx.EndTrace()
 
-	executable := "prebuilts/build-tools/" + config.HostPrebuiltTag() + "/bin/ninja"
+	executable := config.PrebuiltBuildTool("ninja")
 	args := []string{
 		"-d", "keepdepfile",
 	}