terminal,proc: Improved goroutine printing

Three locations are returned for goroutines: its current location,
its current location excluding unexported runtime functions and
the location of its go instruction.
The command 'goroutines' takes a new parameter to select which
location to print (defaulting to current location w/o runtime)

proc/proc.go

@@ -487,9 +487,7 @@ func (dbp *Process) GoroutinesInfo() ([]*G, error) {
 			}
 			g.thread = thread
 			// Prefer actual thread location information.
-			g.File = loc.File
-			g.Line = loc.Line
-			g.Func = loc.Fn
+			g.Current = *loc
 		}
 		if g.Status != Gdead {
 			allg = append(allg, g)