regparse.h: ANSI alias rule fix

* regparse.h (SET_NTYPE): get rid of breaking strict aliasing.
  patch by Zarko Todorovski in [ruby-core:71953].  [Bug #11790]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52999 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Dec  9 17:02:03 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* regparse.h (SET_NTYPE): get rid of breaking strict aliasing.
+	  patch by Zarko Todorovski in [ruby-core:71953].  [Bug #11790]
+
 Wed Dec  9 16:10:37 2015  Koichi Sasada  <ko1@atdot.net>
 
 	* vm.c (rb_vm_cref_in_context): Module#define_method in non-class

regparse.h

@@ -67,7 +67,11 @@ RUBY_SYMBOL_EXPORT_BEGIN
                        BIT_NT_CANY | BIT_NT_BREF)) != 0)
 
 #define NTYPE(node)             ((node)->u.base.type)
-#define SET_NTYPE(node, ntype)   (node)->u.base.type = (ntype)
+#define SET_NTYPE(node, ntype) \
+    do { \
+	int value = ntype; \
+	memcpy(&((node)->u.base.type), &value, sizeof(int)); \
+    } while (0)
 
 #define NSTR(node)         (&((node)->u.str))
 #define NCCLASS(node)      (&((node)->u.cclass))