Add an unsafe method view_mut_raw (#1850)

* adding .vscode folder to .gitignore

* Adding view_mut_raw to generated arrays

* test populating rust vector from JS  function

* Uint32Array test, need to make it generic

* Add doc + more test cases

* replacing macro-generated tests with generic test function

it is cleaner, safer and better that way

* improving rustdoc

crates/js-sys/src/lib.rs

@@ -4792,6 +4792,31 @@ macro_rules! arrays {
                 )
             }
 
+            /// Creates a JS typed array which is a view into wasm's linear
+            /// memory at the specified pointer with specified length.
+            ///
+            /// This function returns a new typed array which is a view into
+            /// wasm's memory. This view does not copy the underlying data.
+            ///
+            /// # Unsafety
+            ///
+            /// Views into WebAssembly memory are only valid so long as the
+            /// backing buffer isn't resized in JS. Once this function is called
+            /// any future calls to `Box::new` (or malloc of any form) may cause
+            /// the returned value here to be invalidated. Use with caution!
+            ///
+            /// Additionally the returned object can be safely mutated,
+            /// the changes are guranteed to be reflected in the input array.
+            pub unsafe fn view_mut_raw(ptr: *mut $ty, length: usize) -> $name {
+                let buf = wasm_bindgen::memory();
+                let mem = buf.unchecked_ref::<WebAssembly::Memory>();
+                $name::new_with_byte_offset_and_length(
+                    &mem.buffer(),
+                    ptr as u32,
+                    length as u32
+                )
+            }
+
             fn raw_copy_to(&self, dst: &mut [$ty]) {
                 let buf = wasm_bindgen::memory();
                 let mem = buf.unchecked_ref::<WebAssembly::Memory>();