runtime/pprof: write heap statistics to heap profile always

This is a duplicate of CL 9491.
That CL broke the build due to pprof shortcomings
and was reverted in CL 9565.

CL 9623 fixed pprof, so this can go in again.

Fixes #10659.

Change-Id: If470fc90b3db2ade1d161b4417abd2f5c6c330b8
Reviewed-on: https://go-review.googlesource.com/10212Reviewed-by: Matthew Dempsky <mdempsky@google.com>

doc/go1.5.txt

@@ -66,6 +66,7 @@ reflect: add ArrayOf (https://golang.org/cl/4111)
 reflect: add FuncOf (https://golang.org/cl/1996)
 runtime, syscall: use SYSCALL instruction on FreeBSD (Go 1.5 now requires FreeBSD 8-STABLE+) (https://golang.org/cl/3020)
 runtime, syscall: use get_random_bytes syscall for NaCl (Go 1.5 now requires NaCl SDK pepper-39 or above) (https://golang.org/cl/1755)
+runtime/pprof: memory profiles include overall memory statistics by default (https://golang.org/cl/9491)
 strings: add Compare(x, y string) int, for symmetry with bytes.Compare (https://golang.org/cl/2828)
 syscall: Add Foreground and Pgid to SysProcAttr (https://golang.org/cl/5130)
 syscall: add missing Syscall9 for darwin/amd64 (https://golang.org/cl/6555)

src/runtime/pprof/pprof.go

@@ -442,7 +442,6 @@ func writeHeap(w io.Writer, debug int) error {
 
 	// Print memstats information too.
 	// Pprof will ignore, but useful for people
-	if debug > 0 {
 	s := new(runtime.MemStats)
 	runtime.ReadMemStats(s)
 	fmt.Fprintf(w, "\n# runtime.MemStats\n")
@@ -470,7 +469,6 @@ func writeHeap(w io.Writer, debug int) error {
 	fmt.Fprintf(w, "# NumGC = %d\n", s.NumGC)
 	fmt.Fprintf(w, "# EnableGC = %v\n", s.EnableGC)
 	fmt.Fprintf(w, "# DebugGC = %v\n", s.DebugGC)
-	}
 
 	if tw != nil {
 		tw.Flush()