Add getter for lineMode and echoMode for Stdin.

runtime/bin/stdin_macos.cc

Index: runtime/bin/stdin_macos.cc
diff --git a/runtime/bin/stdin_macos.cc b/runtime/bin/stdin_macos.cc
index 0bea869609749e059a7a639eae818fcdab9d67f7..a8afb77ecefbc376f04a8899c12c303f6160fa93 100644
--- a/runtime/bin/stdin_macos.cc
+++ b/runtime/bin/stdin_macos.cc
@@ -25,6 +25,13 @@ int Stdin::ReadByte() {
 }
 
 
+bool Stdin::GetEchoMode() {
+  struct termios term;
+  tcgetattr(fileno(stdin), &term);
+  return (term.c_lflag & ECHO) != 0;
+}
+
+
 void Stdin::SetEchoMode(bool enabled) {
   struct termios term;
   tcgetattr(fileno(stdin), &term);
@@ -37,6 +44,13 @@ void Stdin::SetEchoMode(bool enabled) {
 }
 
 
+bool Stdin::GetLineMode() {
+  struct termios term;
+  tcgetattr(fileno(stdin), &term);
+  return (term.c_lflag & ICANON) != 0;
+}
+
+
 void Stdin::SetLineMode(bool enabled) {
   struct termios term;
   tcgetattr(fileno(stdin), &term);