Move GCC diagnostic pragma outside function call to fix build with GCC 4.2.

OK landry@

lang/ruby/2.5/Makefile

@@ -1,9 +1,11 @@
-# $OpenBSD: Makefile,v 1.1.1.1 2018/01/15 23:57:42 jeremy Exp $
+# $OpenBSD: Makefile,v 1.2 2018/01/25 14:34:58 jeremy Exp $
 
 VERSION =		2.5.0
 SHARED_LIBS =		ruby25	0.0
 NEXTVER =		2.6
 
+REVISION-main =		0
+
 PSEUDO_FLAVORS=		no_ri_docs bootstrap
 # Do not build the RI docs on slow arches
 .if ${MACHINE_ARCH:Malpha} || ${MACHINE_ARCH:Marm} || ${MACHINE_ARCH:Mhppa}

lang/ruby/2.5/patches/patch-prelude_c

@@ -0,0 +1,44 @@
+$OpenBSD: patch-prelude_c,v 1.1 2018/01/25 14:34:58 jeremy Exp $
+
+Work on GCC 4.2, which doesn't allow diagnostic pragma inside functions.
+
+Index: prelude.c
+--- prelude.c.orig
++++ prelude.c
+@@ -197,13 +197,13 @@ static const struct {
+ 
+ 
+ #define PRELUDE_STR(n) rb_usascii_str_new_static(prelude_##n.L0, sizeof(prelude_##n))
+-static void
+-prelude_eval(VALUE code, VALUE name, int line)
+-{
+ #ifdef __GNUC__
+ # pragma GCC diagnostic push
+ # pragma GCC diagnostic error "-Wmissing-field-initializers"
+ #endif
++static void
++prelude_eval(VALUE code, VALUE name, int line)
++{
+     static const rb_compile_option_t optimization = {
+ 	TRUE, /* int inline_const_cache; */
+ 	TRUE, /* int peephole_optimization; */
+@@ -217,9 +217,6 @@ prelude_eval(VALUE code, VALUE name, int line)
+ 	FALSE, /* unsigned int coverage_enabled; */
+ 	0, /* int debug_level; */
+     };
+-#ifdef __GNUC__
+-# pragma GCC diagnostic pop
+-#endif
+ 
+     rb_ast_t *ast = rb_parser_compile_string_path(rb_parser_new(), name, code, line);
+     if (!ast->root) {
+@@ -230,6 +227,9 @@ prelude_eval(VALUE code, VALUE name, int line)
+ 				      NULL, ISEQ_TYPE_TOP, &optimization));
+     rb_ast_dispose(ast);
+ }
++#ifdef __GNUC__
++# pragma GCC diagnostic pop
++#endif
+ 
+ void
+ Init_prelude(void)