LLVM: Fix list.insert() when given index is greater than length of the list

[faze-geek]

Consider list.insert(position,element), In python if position is greater than the length of list then by default the element is inserted at position = len(list).
On master -

def f():
    l:list[str] = ["a","b","c","d"]
    l.insert(6,"e")
    print(l)
f()

(lp) faze-geek@DESKTOP-497JDCU:~/lpython/lpython$ python try.py
['a', 'b', 'c', 'd', 'e']
(lp) faze-geek@DESKTOP-497JDCU:~/lpython/lpython$ ./src/bin/lpython try.py
['a', 'b', 'c', 'd', '(null)']    #lpython adds a garbage value

def f():
    l:list[i32] = [1,2,3]
    l.insert(8,4)
    print(l)
f()

(lp) faze-geek@DESKTOP-497JDCU:~/lpython/lpython$ python try.py
[1, 2, 3, 4]
(lp) faze-geek@DESKTOP-497JDCU:~/lpython/lpython$ ./src/bin/lpython try.py
[1, 2, 3, 0]    #lpython adds a garbage value

On branch -

def f():
    l:list[str] = ["a","b","c","d"]
    l.insert(6,"e")
    print(l)
f()

(lp) C:\Users\kunni\lpython>python try.py
['a', 'b', 'c', 'd', 'e']
(lp) C:\Users\kunni\lpython>src\bin\lpython try.py
['a', 'b', 'c', 'd', 'e']

[czgdp1807]

Please add a test for it or point me to any existing tests which verify that your change works correctly.

[faze-geek]

Please add a test for it or point me to any existing tests which verify that your change works correctly.

I have added a test case now. Basically, it handles cases when first argument is greater than list length.

[faze-geek]

@czgdp1807
I investigated the failing logs now. Firstly running the integration_tests/test_list_03.py (where tests have been added) does not give a segmentation error in windows MSVC unlike my WSL setup. This is a seperate issue.
Secondly the c backend in WSL raises the Segmentation Fault when I test indexes greater than the length of the list and as I use an index within the length the error does not occur.
But then this case is a valid edge case as I have shown above, comparing with Cpython -

def test_list_insert_03():
    l1:list[str] = ["a", "b", "c", "d"]
    l1.insert(5,"e")
    s:str = "a"
    i:i32 = 0
    # for i in range(len(l1)):
    #     assert l1[i] == chr(ord(s)+i)
    print(l1)

test_list_insert_03()

(lp) C:\Users\kunni\lpython>python try.py
['a', 'b', 'c', 'd', 'e']

(lp) C:\Users\kunni\lpython>src\bin\lpython try.py
['a', 'b', 'c', 'd', 'e'] 

[czgdp1807]

Seems like an issue with edge case. Note that current_end_point equals len(list) all the times.

lpython/src/libasr/codegen/llvm_utils.cpp

Lines 2252 to 2254 in 57ebbc8

	llvm::Value* LLVMList::len(llvm::Value* list) {
	return LLVM::CreateLoad(*builder, get_pointer_to_current_end_point(list));
	}