migrate allocator calls to alloc_bytes / libc_free

board_fx.sx

@@ -138,7 +138,7 @@ BoardFxAssets :: struct {
             return;
         }
         n := cast(s64) w * cast(s64) h;
-        buf : [*]u8 = xx context.allocator.alloc(n * 4);
+        buf : [*]u8 = xx context.allocator.alloc_bytes(n * 4);
         // Loop locals are hoisted: a block-scoped local declared inside a body
         // that runs hundreds of thousands of times grows the stack per iteration
         // (sx codegen), so the per-pixel tint loop only ASSIGNS pre-declared vars.