[libc++] Define __libcpp_recursive_mutex_t on MIPS architecture

MIPS is a 32-bit architecture, so use the same definition as other
32-bit architectures.

Author: hpoussin

libcxx/include/__cxx03/__thread/support/windows.h

@@ -28,7 +28,8 @@ using __libcpp_timespec_t = ::timespec;
 typedef void* __libcpp_mutex_t;
 #define _LIBCPP_MUTEX_INITIALIZER 0
 
-#if defined(_M_IX86) || defined(__i386__) || defined(_M_ARM) || defined(__arm__)
+#if defined(_M_IX86) || defined(__i386__) || defined(_M_ARM) || defined(__arm__) || defined(_M_MRX000) ||              \
+    defined(__mips__)
 typedef void* __libcpp_recursive_mutex_t[6];
 #elif defined(_M_AMD64) || defined(__x86_64__) || defined(_M_ARM64) || defined(__aarch64__)
 typedef void* __libcpp_recursive_mutex_t[5];

libcxx/include/__thread/support/windows.h

@@ -28,7 +28,8 @@ using __libcpp_timespec_t = ::timespec;
 typedef void* __libcpp_mutex_t;
 #define _LIBCPP_MUTEX_INITIALIZER 0
 
-#if defined(_M_IX86) || defined(__i386__) || defined(_M_ARM) || defined(__arm__)
+#if defined(_M_IX86) || defined(__i386__) || defined(_M_ARM) || defined(__arm__) || defined(_M_MRX000) ||              \
+    defined(__mips__)
 typedef void* __libcpp_recursive_mutex_t[6];
 #elif defined(_M_AMD64) || defined(__x86_64__) || defined(_M_ARM64) || defined(__aarch64__)
 typedef void* __libcpp_recursive_mutex_t[5];