Backport fix for uaf during pcre jit fallback

Backports parts of https://vcs.pcre.org/pcre2?view=revision&revision=1175
fixing https://bugs.exim.org/show_bug.cgi?id=2453.

Author: nikic

ext/pcre/pcre2lib/pcre2_jit_compile.c

@@ -12321,7 +12321,7 @@ if (SLJIT_UNLIKELY(sljit_get_compiler_error(compiler)))
   sljit_free_compiler(compiler);
   SLJIT_FREE(common->optimized_cbracket, allocator_data);
   SLJIT_FREE(common->private_data_ptrs, allocator_data);
-  PRIV(jit_free_rodata)(common->read_only_data_head, compiler->allocator_data);
+  PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
   return PCRE2_ERROR_NOMEMORY;
   }
 
@@ -12375,7 +12375,7 @@ if (SLJIT_UNLIKELY(sljit_get_compiler_error(compiler)))
   sljit_free_compiler(compiler);
   SLJIT_FREE(common->optimized_cbracket, allocator_data);
   SLJIT_FREE(common->private_data_ptrs, allocator_data);
-  PRIV(jit_free_rodata)(common->read_only_data_head, compiler->allocator_data);
+  PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
   return PCRE2_ERROR_NOMEMORY;
   }
 
@@ -12464,7 +12464,7 @@ while (common->currententry != NULL)
     sljit_free_compiler(compiler);
     SLJIT_FREE(common->optimized_cbracket, allocator_data);
     SLJIT_FREE(common->private_data_ptrs, allocator_data);
-    PRIV(jit_free_rodata)(common->read_only_data_head, compiler->allocator_data);
+    PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
     return PCRE2_ERROR_NOMEMORY;
     }
   flush_stubs(common);
@@ -12589,7 +12589,7 @@ while (label_addr != NULL)
 sljit_free_compiler(compiler);
 if (executable_func == NULL)
   {
-  PRIV(jit_free_rodata)(common->read_only_data_head, compiler->allocator_data);
+  PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
   return PCRE2_ERROR_NOMEMORY;
   }
 
@@ -12604,7 +12604,7 @@ else
     /* This case is highly unlikely since we just recently
     freed a lot of memory. Not impossible though. */
     sljit_free_code(executable_func);
-    PRIV(jit_free_rodata)(common->read_only_data_head, compiler->allocator_data);
+    PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
     return PCRE2_ERROR_NOMEMORY;
     }
   memset(functions, 0, sizeof(executable_functions));