Make ctrl-c terminate the current input line and start an empty line, instead of the previous content.

rdar://problem/11412821

llvm-svn: 156510
diff --git a/lldb/tools/driver/IOChannel.cpp b/lldb/tools/driver/IOChannel.cpp
index f14e1b2..2527458 100644
--- a/lldb/tools/driver/IOChannel.cpp
+++ b/lldb/tools/driver/IOChannel.cpp
@@ -50,6 +50,13 @@
     return pos->second.c_str();
 }
 
+void
+IOChannel::EraseCharsBeforeCursor ()
+{
+    const LineInfo *line_info  = el_line(m_edit_line);
+    el_deletestr(m_edit_line, line_info->cursor - line_info->buffer);
+}
+
 unsigned char
 IOChannel::ElCompletionFn (EditLine *e, int ch)
 {