runtime/pprof: write profiles in protobuf format.

Original Change by Daria Kolistratova <[email protected]>

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: I2751345b09a66ee2b6aa64be76cba4cd1c326aa6
Reviewed-on: https://go-review.googlesource.com/32257
Run-TryBot: Michael Matloob <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Alan Donovan <[email protected]>

Author: matloob

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", "text/tabwriter"},
+	"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 {