Fix compile error of tsf benchmark (bytecodealliance#2588)

Explicitly declare readdir_r in gpc_code_gen_util.c.

tests/benchmarks/jetstream/tsf.patch

@@ -1,6 +1,18 @@
+diff -urN tsf-src-org/gpc_code_gen_util.c tsf-src/gpc_code_gen_util.c
+--- tsf-src-org/gpc_code_gen_util.c	2023-09-21 11:12:40.211166472 +0800
++++ tsf-src/gpc_code_gen_util.c	2023-09-21 11:09:13.643170967 +0800
+@@ -34,6 +34,8 @@
+ #include <errno.h>
+ #include <dirent.h>
+
++int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result);
++
+ /* code generation debugging */
+
+ /* NOTE: It is now the case that the count may be incremented multiple times,
 diff -urN tsf-src-org/tsf_internal.h tsf-src/tsf_internal.h
---- tsf-src-org/tsf_internal.h  2023-03-31 10:49:45.000000000 +0800
-+++ tsf-src/tsf_internal.h  2023-05-11 08:18:35.000000000 +0800
+--- tsf-src-org/tsf_internal.h	2023-09-21 11:11:50.843167546 +0800
++++ tsf-src/tsf_internal.h	2023-09-21 11:06:53.031174027 +0800
 @@ -429,6 +429,7 @@
  #endif
              tsf_fsdb_connection_t *connection;
@@ -10,15 +22,15 @@ diff -urN tsf-src-org/tsf_internal.h tsf-src/tsf_internal.h
      } u;
      tsf_limits_t *limits;
 diff -urN tsf-src-org/tsf_ir_speed.c tsf-src/tsf_ir_speed.c
---- tsf-src-org/tsf_ir_speed.c  2023-03-31 10:49:45.000000000 +0800
-+++ tsf-src/tsf_ir_speed.c  2023-05-11 08:18:35.000000000 +0800
+--- tsf-src-org/tsf_ir_speed.c	2023-09-21 11:12:15.699167005 +0800
++++ tsf-src/tsf_ir_speed.c	2023-09-21 11:06:53.031174027 +0800
 @@ -63,6 +63,9 @@
          Program_t *program;
          unsigned elementIndex;
-
+ 
 +        if (!(programIndex % 100))
 +            printf("##programIndex: %u\n", programIndex);
 +
          CS(program = tsf_region_create(sizeof(Program_t)));
-
+         
          program->globals.len = numDecls + numDefns;