Also allow compiled format for clang >= 12

Author: yujincheng08

include/fmt/base.h

@@ -148,6 +148,9 @@ import std;
 #elif defined(__cpp_nontype_template_args) && \
     __cpp_nontype_template_args >= 201911L
 #  define FMT_USE_NONTYPE_TEMPLATE_ARGS 1
+#elif FMT_CLANG_VERSION >= 1200 && FMT_CPLUSPLUS >= 202002L
+// clang 12 already has enough support for {fmt} to use.
+#  define FMT_USE_NONTYPE_TEMPLATE_ARGS 1
 #else
 #  define FMT_USE_NONTYPE_TEMPLATE_ARGS 0
 #endif