Update debugger docs with () and 'cy set'

src/userguide/debugging.rst

@@ -176,6 +176,10 @@ of these commands are analogous to their respective gdb command.
             ob_type = 0x83a3e0
         }
 
+.. function:: cy set cython_variable = value
+
+    Set a Cython variable on the Cython stack to value.
+
 .. function:: cy list
 
     List the source code surrounding the current line.
@@ -228,17 +232,23 @@ gdb expression.
 
     Returns the value of a Cython variable.
 
+.. function:: cy_eval(expression)
+
+    Evaluates Python code in the nearest Python or Cython frame and returns
+    the result of the expression as a gdb value. This gives a new reference
+    if successful, NULL on error.
+
 .. function:: cy_lineno()
 
     Returns the current line number in the selected Cython frame.
 
-
 Example::
 
     (gdb) print $cy_cname("x")
     $1 = "__pyx_v_x"
     (gdb) watch $cy_cvalue("x")
     Hardware watchpoint 13: $cy_cvalue("x")
+    (gdb) cy set my_cython_variable = $cy_eval("{'spam': 'ham'}")
     (gdb) print $cy_lineno()
     $2 = 12