cmd/compile: update a few stale comments

CL 64811 removed dcopy. Update the comment in types.Sym.

The Russquake moved iexport.go. Update the path to it.

WRAPPER is now also used by ABI wrappers, so update the comment since
it's now more general than method wrappers.

Change-Id: Ie0df61dcef7168f6720838cd5c9a66adf546a44f
Reviewed-on: https://go-review.googlesource.com/c/go/+/305269
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/compile/internal/importer/iimport.go

@@ -4,7 +4,7 @@
 // license that can be found in the LICENSE file.
 
 // Indexed package import.
-// See cmd/compile/internal/gc/iexport.go for the export data format.
+// See cmd/compile/internal/typecheck/iexport.go for the export data format.
 
 package importer
 

src/cmd/compile/internal/ir/func.go

@@ -162,7 +162,7 @@ type ScopeID int32
 
 const (
 	funcDupok         = 1 << iota // duplicate definitions ok
-	funcWrapper                   // is method wrapper
+	funcWrapper                   // hide frame from users (elide in tracebacks, don't count as a frame for recover())
 	funcNeedctxt                  // function uses context register (has closure variables)
 	funcReflectMethod             // function calls reflect.Type.Method or MethodByName
 	// true if closure inside a function; false if a simple function or a

src/cmd/compile/internal/types/sym.go

@@ -32,7 +32,7 @@ type Sym struct {
 	Pkg  *Pkg
 	Name string // object name
 
-	// saved and restored by dcopy
+	// saved and restored by Pushdcl/Popdcl
 	Def        Object   // definition: ONAME OTYPE OPACK or OLITERAL
 	Block      int32    // blocknumber to catch redeclaration
 	Lastlineno src.XPos // last declaration for diagnostic

src/cmd/internal/obj/textflag.go

@@ -27,7 +27,8 @@ const (
 	// This data contains no pointers.
 	NOPTR = 16
 
-	// This is a wrapper function and should not count as disabling 'recover'.
+	// This is a wrapper function and should not count as
+	// disabling 'recover' or appear in tracebacks by default.
 	WRAPPER = 32
 
 	// This function uses its incoming context register.