SDL: Compile with recursive mutexes for emscripten

SDL Commits
1 
From 6dbca7c911acec36a2258801ad55f766ce5d6aa4 Mon Sep 17 00:00:00 2001
From: Connor Clark <[EMAIL REDACTED]>
Date: Wed, 6 Apr 2022 20:48:41 -0500
Subject: [PATCH] Compile with recursive mutexes for emscripten

Emscripten actually does support recursive mutexes, so no need to use SDL's fake recursive code.

Background: #5428, #5479
---
 include/SDL_config_emscripten.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/SDL_config_emscripten.h b/include/SDL_config_emscripten.h
index 7efe32373dc..028777df1d3 100644
--- a/include/SDL_config_emscripten.h
+++ b/include/SDL_config_emscripten.h
@@ -185,6 +185,7 @@
 /* Enable various threading systems */
 #ifdef __EMSCRIPTEN_PTHREADS__
 #define SDL_THREAD_PTHREAD 1
+#define SDL_THREAD_PTHREAD_RECURSIVE_MUTEX 1
 #endif
 
 /* Enable various timer systems */