config/pcre: Improved support for cross-compiling

This commit changes the logic used to determine if pcre_jit_exec is
available from a run-time to a compile-time check.

configure.ac

@@ -793,12 +793,14 @@ return 0;
 
     if test "x$pcre_jit_works" = "xyes"; then
 
-       AC_MSG_CHECKING(for PCRE JIT EXEC support usability)
+       AC_MSG_CHECKING(for PCRE JIT exec availability)
-       AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+       AC_LINK_IFELSE(
+           [AC_LANG_PROGRAM(
+               [
                   #include <pcre.h>
                   #include <string.h>
-                          ]],
+               ],
-           [[
+               [
                    const char *error;
                    int err_offset;
                    pcre *re = pcre_compile("(a|b|c|d)", 0, &error, &err_offset,NULL);
@@ -809,16 +811,15 @@ return 0;
                    if (stack == 0)
                        exit(EXIT_FAILURE);
                    int ret = pcre_jit_exec(re, study, "apple", 5, 0, 0, NULL, 0, stack);
-           if (ret != 0)
+                   exit(ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
-               exit(EXIT_FAILURE);
+               ])],
-           exit(EXIT_SUCCESS);
+           [pcre_jit_exec_available="yes" ],
-           ]])],[ pcre_jit_exec_works=yes ],[:]
+           [pcre_jit_exec_available="no" ])
-       )
+       if test "x$pcre_jit_exec_available" != "xyes"; then
-       if test "x$pcre_jit_exec_works" != "xyes"; then
            AC_MSG_RESULT(no)
        else
            AC_MSG_RESULT(yes)
-           AC_DEFINE([PCRE_HAVE_JIT_EXEC], [1], [Pcre with JIT compiler support enabled supporting pcre_jit_exec])
+           AC_DEFINE([PCRE_HAVE_JIT_EXEC], [1], [PCRE with JIT compiler support enabled supporting pcre_jit_exec])
        fi
     else
         AC_MSG_RESULT(no)