fix indexing error in Array.insert family

Author: dgriffie79

core/container/array.onyx

@@ -166,7 +166,7 @@ Array.insert :: (arr: &[..] $T, idx: u32, x: T) -> bool {
     if !Array.ensure_capacity(arr, arr.count + 1) do return false;
 
     arr.count += 1;
-    while i := arr.count; i > idx {
+    while i := arr.count - 1; i > idx {
         arr.data[i] = arr.data[i - 1];
         i -= 1;
     }
@@ -181,7 +181,7 @@ Array.insert :: (arr: &[..] $T, idx: u32, new_arr: [] T) -> bool {
     if !Array.ensure_capacity(arr, arr.count + new_arr.count) do return false;
 
     arr.count += new_arr.count;
-    while i := arr.count; i > idx {
+    while i := arr.count - 1; i > idx {
         arr.data[i] = arr.data[i - new_arr.count];
         i -= 1;
     }
@@ -198,7 +198,7 @@ Array.insert_empty :: (arr: &[..] $T, idx: u32) -> bool {
     if !Array.ensure_capacity(arr, arr.count + 1) do return false;
 
     arr.count += 1;
-    while i := arr.count; i > idx {
+    while i := arr.count - 1; i > idx {
         arr.data[i] = arr.data[i - 1];
         i -= 1;
     }