- Temp allocator now supports more than 2 in-flight stacks.

- Printing stacktrace uses its own temp allocator.
- `@pool` no longer takes an argument.
- `Allocator` interface removes `mark` and `reset`.
- DynamicArenaAllocator has changed init function.
- Added `BackedArenaAllocator` which is allocated to a fixed size, then allocates on the backing allocator and supports mark/reset.

lib/std/io/os/ls.c3

@@ -29,7 +29,7 @@ fn PathList? native_ls(Path dir, bool no_dirs, bool no_symlinks, String mask, Al
 	PathList list;
 	list.init(allocator);
 
-	@pool(allocator)
+	@pool()
 	{
 		WString result = dir.str_view().tconcat(`\*`).to_temp_wstring()!!;
 		Win32_WIN32_FIND_DATAW find_data;
@@ -39,7 +39,7 @@ fn PathList? native_ls(Path dir, bool no_dirs, bool no_symlinks, String mask, Al
 		do
 		{
 			if (no_dirs && (find_data.dwFileAttributes & win32::FILE_ATTRIBUTE_DIRECTORY)) continue;
-			@pool(allocator)
+			@pool()
 			{
 				String filename = string::tfrom_wstring((WString)&find_data.cFileName)!;
 				if (filename == ".." || filename == ".") continue;

lib/std/io/os/temp_directory.c3

@@ -11,7 +11,7 @@ fn Path? native_temp_directory(Allocator allocator) @if(!env::WIN32)
 	return path::new(allocator, "/tmp");
 }
 
-fn Path? native_temp_directory(Allocator allocator) @if(env::WIN32) => @pool(allocator)
+fn Path? native_temp_directory(Allocator allocator) @if(env::WIN32) => @pool()
 {
 	Win32_DWORD len = win32::getTempPathW(0, null);
 	if (!len) return io::GENERAL_ERROR?;