cmd/compile/internal/syntax: replace inlined statement lists with syntax.BlockStmt

This simplifies the code and removes a premature optimization.
It increases the amount of allocated syntax.Node space by ~0.4%
for parsing all of std lib, which is negligible.

Before the change (best of 5 runs):

  $ go test -run StdLib -fast
  parsed 1517022 lines (3394 files) in 793.487886ms (1911840 lines/s)
  allocated 387.086Mb (267B/line, 487.828Mb/s)

After the change (best of 5 runs):

  $ go test -run StdLib -fast
  parsed 1516911 lines (3392 files) in 805.028655ms (1884294 lines/s)
  allocated 388.466Mb (268B/line, 482.549Mb/s)

Change-Id: Id19d6210fdc62393862ba3b04913352d95c599be
Reviewed-on: https://go-review.googlesource.com/38439
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/src/cmd/compile/internal/syntax/parser_test.go b/src/cmd/compile/internal/syntax/parser_test.go
index 06c74cbfba..4c317dab60 100644
--- a/src/cmd/compile/internal/syntax/parser_test.go
+++ b/src/cmd/compile/internal/syntax/parser_test.go
@@ -23,10 +23,7 @@ var src_ = flag.String("src", "parser.go", "source file to parse")
 var verify = flag.Bool("verify", false, "verify idempotent printing")
 
 func TestParse(t *testing.T) {
-	_, err := ParseFile(*src_, nil, nil, 0)
-	if err != nil {
-		t.Fatal(err)
-	}
+	ParseFile(*src_, func(err error) { t.Error(err) }, nil, 0)
 }
 
 func TestStdLib(t *testing.T) {
@@ -81,7 +78,7 @@ func TestStdLib(t *testing.T) {
 	dm := float64(m2.TotalAlloc-m1.TotalAlloc) / 1e6
 
 	fmt.Printf("parsed %d lines (%d files) in %v (%d lines/s)\n", lines, count, dt, int64(float64(lines)/dt.Seconds()))
-	fmt.Printf("allocated %.3fMb (%dB/line, %.3fMb/s)\n", dm, uint64(dm*(1<<20)/float64(lines)), dm/dt.Seconds())
+	fmt.Printf("allocated %.3fMb (%.3fMb/s)\n", dm, dm/dt.Seconds())
 }
 
 func walkDirs(t *testing.T, dir string, action func(string)) {