[vkgen] Use typedef name for structs

Using the typedef name makes using structs declared as

    typedef struct foo_s { ... } foo_t;

easier and cleaner. Sure, I could have written the "struct foo_s" for
the output name, but I'm much more likely to look for foo_t than foo_s
when checking the generated code.

libs/video/renderer/vulkan/vkgen/vkalias.r

@@ -6,6 +6,15 @@
 #include "vkstruct.h"
 
 @implementation Alias
+-initWithType: (qfot_type_t *) type
+{
+	if (!(self = [super initWithType: type])) {
+		return nil;
+	}
+	[[self resolveType] setAlias: self];
+	return self;
+}
+
 -(string) name
 {
 	return type.alias.name;

libs/video/renderer/vulkan/vkgen/vkstruct.r

@@ -245,6 +245,9 @@
 	if (outname) {
 		return outname;
 	}
+	if (alias) {
+		return [alias name];
+	}
 	return [self name];
 }
 

libs/video/renderer/vulkan/vkgen/vktype.h

@@ -7,6 +7,7 @@
 @interface Type: Object
 {
 	qfot_type_t *type;
+	Type       *alias;
 }
 +fromType: (qfot_type_t *) type;
 /**	\warning	returned string is ephemeral
@@ -15,6 +16,7 @@
 /**	\warning	returned string is ephemeral
 */
 -(string) name;
+-(void) setAlias: (Type *) alias;
 -(void) addToQueue;
 -(Type *) resolveType;
 +(Type *) findType: (qfot_type_t *) type;

libs/video/renderer/vulkan/vkgen/vktype.r

@@ -86,6 +86,13 @@ static string get_type_key (void *type, void *unused)
 	return type.encoding;
 }
 
+-(void) setAlias: (Type *) alias
+{
+	if (!self.alias) {
+		self.alias = alias;
+	}
+}
+
 -(void) addToQueue
 {
 	string name = [self name];