proc/test/support: implement EnableDWZCompression

The EnableDWZCompression flag allows tests to request BuildFixture to
run "dwz" on the Fixture's resulting binary to compress/deduplicate its
DWARF sections.

pkg/proc/test/support.go

@@ -54,6 +54,7 @@ const (
 	LinkStrip BuildFlags = 1 << iota
 	EnableCGOOptimization
 	EnableInlining
+	EnableDWZCompression
 )
 
 func BuildFixture(name string, flags BuildFlags) Fixture {
@@ -110,6 +111,15 @@ func BuildFixture(name string, flags BuildFlags) Fixture {
 		os.Exit(1)
 	}
 
+	if flags&EnableDWZCompression != 0 {
+		cmd := exec.Command("dwz", tmpfile)
+		if out, err := cmd.CombinedOutput(); err != nil {
+			fmt.Printf("Error running dwz on %s: %s\n", tmpfile, err)
+			fmt.Printf("%s\n", string(out))
+			os.Exit(1)
+		}
+	}
+
 	source, _ := filepath.Abs(path)
 	source = filepath.ToSlash(source)