cmd/compile: update/remove outdated comments

Change-Id: I5a74be1593dca8ba5e0829f0bae35dc9ce702671
Reviewed-on: https://go-review.googlesource.com/32672Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/compile/internal/gc/bexport.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 // Binary package export.
-// (see fmt.go, parser.go as "documentation" for how to use/setup data structures)
 
 /*
 1) Export data encoding principles:
@@ -71,8 +70,9 @@ same type was imported before via another import, the importer must use
 the previously imported type pointer so that we have exactly one version
 (i.e., one pointer) for each named type (and read but discard the current
 type encoding). Unnamed types simply encode their respective fields.
-Aliases are encoded starting with their name followed by the original
-(aliased) object.
+Aliases are encoded starting with their name followed by the qualified
+identifier denoting the original (aliased) object, which was exported
+earlier.
 
 In the encoding, some lists start with the list length. Some lists are
 terminated with an end marker (usually for lists where we may not know

src/cmd/compile/internal/gc/bimport.go

@@ -436,16 +436,13 @@ func (p *importer) typ() *Type {
 	var t *Type
 	switch i {
 	case namedTag:
-		// parser.go:hidden_importsym
 		p.pos()
 		tsym := p.qualifiedName()
 
-		// parser.go:hidden_pkgtype
 		t = pkgtype(tsym)
 		p.typList = append(p.typList, t)
 
 		// read underlying type
-		// parser.go:hidden_type
 		t0 := p.typ()
 		p.importtype(t, t0)
 
@@ -461,8 +458,6 @@ func (p *importer) typ() *Type {
 
 		// read associated methods
 		for i := p.int(); i > 0; i-- {
-			// parser.go:hidden_fndcl
-
 			p.pos()
 			sym := p.fieldSym()
 
@@ -574,7 +569,6 @@ func (p *importer) qualifiedName() *Sym {
 	return pkg.Lookup(name)
 }
 
-// parser.go:hidden_structdcl_list
 func (p *importer) fieldList() (fields []*Field) {
 	if n := p.int(); n > 0 {
 		fields = make([]*Field, n)
@@ -585,7 +579,6 @@ func (p *importer) fieldList() (fields []*Field) {
 	return
 }
 
-// parser.go:hidden_structdcl
 func (p *importer) field() *Field {
 	p.pos()
 	sym := p.fieldName()
@@ -611,7 +604,6 @@ func (p *importer) field() *Field {
 	return f
 }
 
-// parser.go:hidden_interfacedcl_list
 func (p *importer) methodList() (methods []*Field) {
 	if n := p.int(); n > 0 {
 		methods = make([]*Field, n)
@@ -622,7 +614,6 @@ func (p *importer) methodList() (methods []*Field) {
 	return
 }
 
-// parser.go:hidden_interfacedcl
 func (p *importer) method() *Field {
 	p.pos()
 	sym := p.fieldName()
@@ -636,7 +627,6 @@ func (p *importer) method() *Field {
 	return f
 }
 
-// parser.go:sym,hidden_importsym
 func (p *importer) fieldName() *Sym {
 	name := p.string()
 	if p.version == 0 && name == "_" {
@@ -654,7 +644,6 @@ func (p *importer) fieldName() *Sym {
 	return pkg.Lookup(name)
 }
 
-// parser.go:ohidden_funarg_list
 func (p *importer) paramList() []*Field {
 	i := p.int()
 	if i == 0 {
@@ -674,7 +663,6 @@ func (p *importer) paramList() []*Field {
 	return fs
 }
 
-// parser.go:hidden_funarg
 func (p *importer) param(named bool) *Field {
 	f := newField()
 	f.Type = p.typ()