ICU-10183 revert mutexes to platform code while sorting dependencies from std::mutex.

diff --git a/icu4c/source/common/putilimp.h b/icu4c/source/common/putilimp.h
index 73defd9d072809459ee8693f221ad4a6928e2999..e4821e420bfdd0536af99dbf97c75afe97644edb 100644 (file)
--- a/icu4c/source/common/putilimp.h
+++ b/icu4c/source/common/putilimp.h
@@ -245,7 +245,7 @@ typedef size_t uintptr_t;
 #ifdef U_HAVE_STD_MUTEX
     /* Use the predefined value. */
 #else
-#    define U_HAVE_STD_MUTEX 1
+#    define U_HAVE_STD_MUTEX 0
 #endif
 
 /*===========================================================================*/