progress on collaping arena->allocator info code paths (did some generic selection changes)

Going to offload prefix naming to the c11.refactor and cpp17.refactor

code/base/markup.h

@@ -17,7 +17,7 @@ set_thread_namef(char *fmt, ...)
 
 	va_list args;
 	va_start(args, fmt);
-	String8 string = push_str8fv(scratch.arena, fmt, args);
+	String8 string = str8fv(scratch.arena, fmt, args);
 	set_thread_name(string);
 	va_end(args);