Mass rewrite dtors to use "= default".

A simple search and replace with sed s/::~\(.*\) {}$/::~\1 = default;/
works surprisingly well.

Change-Id: Ie958265266e504006061e8f1b957046dfecd70dc
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/70251
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fxjs/xfa/cjx_subform.cpp b/fxjs/xfa/cjx_subform.cpp
index 8a72b5b..1ea6b56 100644
--- a/fxjs/xfa/cjx_subform.cpp
+++ b/fxjs/xfa/cjx_subform.cpp
@@ -28,7 +28,7 @@
   DefineMethods(MethodSpecs);
 }
 
-CJX_Subform::~CJX_Subform() {}
+CJX_Subform::~CJX_Subform() = default;
 
 bool CJX_Subform::DynamicTypeIs(TypeTag eType) const {
   return eType == static_type__ || ParentType__::DynamicTypeIs(eType);