Fix struct usage.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65872 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

coroutine/win32/Context.h

@@ -19,10 +19,10 @@ extern "C" {
 /* This doesn't include thread information block */
 const size_t COROUTINE_REGISTERS = 4;
 
-struct coroutine_context
+typedef struct
 {
 	void **stack_pointer;
-};
+} coroutine_context;
 
 typedef void(__fastcall * coroutine_start)(coroutine_context *from, coroutine_context *self);
 

coroutine/win64/Context.h

@@ -19,10 +19,10 @@ extern "C" {
 const size_t COROUTINE_REGISTERS = 8;
 const size_t COROUTINE_XMM_REGISTERS = 1+10*2;
 
-struct coroutine_context
+typedef struct
 {
 	void **stack_pointer;
-};
+} coroutine_context;
 
 typedef void(* coroutine_start)(coroutine_context *from, coroutine_context *self);