runtime/pprof: write profiles in protobuf format.

Added functions with suffix proto and stuff from pprof tool to translate
to protobuf. Done as the profile proto is more extensible than the legacy
pprof format and is pprof's preferred profile format. Large part was taken
from https://github.com/google/pprof tool. Tested by hand and compared the
result with translated by pprof tool, profiles are identical.
Fixes #16093
Change-Id: I5acdb2809cab0d16ed4694fdaa7b8ddfd68df11e
Reviewed-on: https://go-review.googlesource.com/30556
Run-TryBot: Michael Matloob <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>

Author: DarKol13

src/go/build/deps_test.go

@@ -170,12 +170,14 @@ var pkgDeps = map[string][]string{
 	"log": {"L1", "os", "fmt", "time"},
 
 	// Packages used by testing must be low-level (L2+fmt).
-	"regexp":         {"L2", "regexp/syntax"},
-	"regexp/syntax":  {"L2"},
-	"runtime/debug":  {"L2", "fmt", "io/ioutil", "os", "time"},
-	"runtime/pprof":  {"L2", "fmt", "os", "text/tabwriter"},
-	"runtime/trace":  {"L0"},
-	"text/tabwriter": {"L2"},
+	"regexp":                            {"L2", "regexp/syntax"},
+	"regexp/syntax":                     {"L2"},
+	"runtime/debug":                     {"L2", "fmt", "io/ioutil", "os", "time"},
+	"runtime/pprof/internal/profile":    {"L2"},
+	"runtime/pprof/internal/protopprof": {"L2", "fmt", "runtime/pprof/internal/profile", "os", "time"},
+	"runtime/pprof":                     {"L2", "fmt", "runtime/pprof/internal/profile", "runtime/pprof/internal/protopprof", "time"},
+	"runtime/trace":                     {"L0"},
+	"text/tabwriter":                    {"L2"},
 
 	"testing":          {"L2", "flag", "fmt", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
 	"testing/iotest":   {"L2", "log"},

src/runtime/crash_cgo_test.go

@@ -271,10 +271,11 @@ func testCgoPprof(t *testing.T, buildArg, runArg string) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	fn := strings.TrimSpace(string(got))
 	defer os.Remove(fn)
 
-	cmd := testEnv(exec.Command(testenv.GoToolPath(t), "tool", "pprof", "-top", "-nodecount=1", exe, fn))
+	cmd := testEnv(exec.Command(testenv.GoToolPath(t), "tool", "pprof", "-top", "-nodecount=1", "-symbolize=force", exe, fn))
 
 	found := false
 	for i, e := range cmd.Env {