Fix for ruby 2.4 heap overflow

This fixes the ruby 2.4 heap overflow reported by
timo.myyra@wickedbsd.net. The underlying cause was they renamed
variables in gc.c but forgot to update the configure script.

Ruby bug report: https://bugs.ruby-lang.org/issues/13438

Tested briefly on amd64, I'll run more tests soon. Assuming no
problems I'll be committing this weekend unless I hear objections.

Thanks,
Jeremy

Index: Makefile
===================================================================
RCS file: /cvs/ports/lang/ruby/2.4/Makefile,v
retrieving revision 1.3
diff -u -p -r1.3 Makefile
--- Makefile 24 Mar 2017 14:39:05 -0000 1.3
+++ Makefile 14 Apr 2017 23:16:12 -0000
@@ -16,6 +16,8 @@ PKGNAME-ri_docs = ruby24-ri_docs-${VERSI
PKG_ARCH-ri_docs = *
WANTLIB-ri_docs = # empty

+REVISION-main = 0
+
NEXTVER = 2.5
PKGSPEC-main = ruby->=${RUBYLIBREV},<${NEXTVER}

Index: patches/patch-configure
===================================================================
RCS file: /cvs/ports/lang/ruby/2.4/patches/patch-configure,v
retrieving revision 1.2
diff -u -p -r1.2 patch-configure
--- patches/patch-configure 24 Mar 2017 14:39:05 -0000 1.2
+++ patches/patch-configure 14 Apr 2017 23:15:58 -0000
@@ -5,8 +5,10 @@ Fix so name, checking for DOT and DOXYGE
Override the arch setting to remove OpenBSD version from it,
so ports don't have to be bumped when OpenBSD version changes.

+Rename HEAP_ALIGN_LOG to HEAP_PAGE_ALIGN_LOG to fix heap overflow.
+
--- configure.orig Tue Mar 21 22:56:10 2017
-+++ configure Wed Mar 22 08:33:15 2017
++++ configure Fri Apr 14 16:15:30 2017
@@ -424,7 +424,7 @@ if test -z "$2"; then :

else
@@ -16,6 +18,21 @@ so ports don't have to be bumped when Op
if test "$FOLD"; then :

echo "$2" | fold -s -w50 |
+@@ -19464,12 +19464,12 @@ fi
+ colorize_result "$rb_cv_page_size_log" ; }
+ if test $rb_cv_page_size_log != no; then
+ cat >>confdefs.h <<_ACEOF
+-#define HEAP_ALIGN_LOG $rb_cv_page_size_log
++#define HEAP_PAGE_ALIGN_LOG $rb_cv_page_size_log
+ _ACEOF
+
+ else
+ cat >>confdefs.h <<_ACEOF
+-#define HEAP_ALIGN_LOG 12
++#define HEAP_PAGE_ALIGN_LOG 12
+ _ACEOF
+
+ fi
@@ -25601,7 +25601,7 @@ esac
openbsd*|mirbsd*) :