Swift: turn some generated paths to relative

Author: redsun82

swift/codegen/templates/cpp_classes.mustache

@@ -7,7 +7,7 @@
 #include <vector>
 
 #include "{{include_dir}}/TrapLabel.h"
-#include "{{include_dir}}/TrapEntries.h"
+#include "./TrapEntries.h"
 
 namespace {{namespace}} {
 {{#classes}}

swift/codegen/templates/trap_traps.mustache

@@ -6,7 +6,7 @@
 #include <string>
 
 #include "{{include_dir}}/TrapLabel.h"
-#include "{{include_dir}}/TrapTags.h"
+#include "./TrapTags.h"
 
 namespace {{namespace}} {
 {{#traps}}