[lldb][gui] use just '#2' instead of 'frame #2' in the threads/frame view

Since the threads/frame view is taking only a small part on the right side
of the screen, only a part of the function name of each frame is visible.
It seems rather wasteful to spell out 'frame' there when it's obvious
that it is a frame, it's better to use the space for more of the function
name.

Differential Revision: https://reviews.llvm.org/D122998

Author: llunak

lldb/source/Core/IOHandlerCursesGUI.cpp

@@ -5016,8 +5016,7 @@ class FrameTreeDelegate : public TreeDelegate {
 public:
   FrameTreeDelegate() : TreeDelegate() {
     FormatEntity::Parse(
-        "frame #${frame.index}: {${function.name}${function.pc-offset}}}",
-        m_format);
+        "#${frame.index}: {${function.name}${function.pc-offset}}}", m_format);
   }
 
   ~FrameTreeDelegate() override = default;

lldb/test/API/commands/gui/expand-threads-tree/TestGuiExpandThreadsTree.py

@@ -33,7 +33,7 @@ def test_gui(self):
         self.child.expect_exact("Threads")
 
         # The thread running thread_start_routine should be expanded.
-        self.child.expect_exact("frame #0: break_here")
+        self.child.expect_exact("#0: break_here")
 
         # Exit GUI.
         self.child.send(escape_key)
@@ -47,7 +47,7 @@ def test_gui(self):
         self.child.expect_exact("Threads")
 
         # The main thread should be expanded.
-        self.child.expect("frame #\d+: main")
+        self.child.expect("#\d+: main")
 
         # Quit the GUI
         self.child.send(escape_key)