std: introduce orderedRemoveMany

[andrewrk]

This algorithm is non-trivial and makes sense for any data structure that acts as an array list, so I thought it would make sense as a method.

I have a real world case for this in a music player application (deleting queue items).

Adds the method to:

• ArrayList
• ArrayHashMap
• MultiArrayList

[jacobly0]

Idea for a better array list impl:

        pub fn orderedRemoveMany(self: *Self, sorted_indexes: []const usize) void {
            if (sorted_indexes.len == 0) return;
            var shift: usize = 1;
            for (sorted_indexes[0..sorted_indexes.len - 1], sorted_indexes[1..]) |removed, end| {
                if (removed == end) continue; // allows duplicates in `sorted_indexes`
                const start = removed + 1;
                const len = end - start; // safety checks `sorted_indexes` are sorted
                @memmove(self.items[start - shift ..][0..len], self.items[start ..][0..len]); // safety checks inital `sorted_indexes` are in range
                shift += 1;
            }
            const start = sorted_indexes[sorted_indexes.len - 1] + 1;
            const end = self.items.len;
            const len = end - start; // safety checks final `sorted_indexes` are in range
            @memmove(self.items[start - shift ..][0..len], self.items[start..][0..len]);
            self.items.len = end - shift;
        }

[andrewrk]

Nice! You didn't implement @memmove in the x86 backend when I wasn't looking, did you?

Ah, it's only not implemented for COFF.

Also noticed CI has no std lib test coverage for x86 backend on Windows, so I don't even need to disable the new tests here.

[andrewrk]

I'm not in any rush to merge this, I'll let it sit until wrangle-writer-buffering branch is complete, and include a zig1.wasm update there, and update to use @memmove there.

[andrewrk]

tested locally with stage3/bin/zig build test -Dskip-release -Dskip-non-native