Implement list insert primitive

Author: vsakkas

mypyc/primitives/list_ops.py

@@ -105,6 +105,14 @@
     c_function_name='CPyList_Count',
     error_kind=ERR_MAGIC)
 
+# list.insert(index, obj)
+method_op(
+    name='insert',
+    arg_types=[list_rprimitive, int_rprimitive, object_rprimitive],
+    return_type=int_rprimitive,
+    c_function_name='PyList_Insert',
+    error_kind=ERR_MAGIC)
+
 # list * int
 binary_op(
     name='*',

mypyc/test-data/irbuild-lists.test

@@ -233,3 +233,18 @@ L0:
     r2 = r1 >= 0 :: signed
     r3 = truncate r1: int32 to builtins.bool
     return r3
+
+[case testListInsert]
+from typing import List
+def f(x: List[int], y: int) -> None:
+    x.insert(0, y)
+[out]
+def f(x, y):
+    x :: list
+    y :: int
+    r0 :: object
+    r1 :: int
+L0:
+    r0 = box(int, y)
+    r1 = PyList_Insert(x, 0, r0)
+    return 1

mypyc/test-data/run-lists.test

@@ -103,6 +103,12 @@ pop(l, -2)
 assert l == [1, 3]
 assert count(l, 1) == 1
 assert count(l, 2) == 0
+l.insert(0, 0)
+assert l == [0, 1, 2]
+l.insert(3, 3)
+assert l == [0, 1, 2, 3]
+l.insert(2, 2)
+assert l == [0, 1, 2, 2, 3]
 
 [case testListOfUserDefinedClass]
 class C: