Add check for trivial string equality

core/fxcrt/fx_basic_bstring.cpp

Index: core/fxcrt/fx_basic_bstring.cpp
diff --git a/core/fxcrt/fx_basic_bstring.cpp b/core/fxcrt/fx_basic_bstring.cpp
index d0ba1af5ba7bb7614f5ad0d2f034aa04e67c211f..0b9d9873d8dc02f647d615916a6f35beab136fcf 100644
--- a/core/fxcrt/fx_basic_bstring.cpp
+++ b/core/fxcrt/fx_basic_bstring.cpp
@@ -202,6 +202,9 @@ bool CFX_ByteString::operator==(const CFX_ByteStringC& str) const {
 }
 
 bool CFX_ByteString::operator==(const CFX_ByteString& other) const {
+  if (m_pData == other.m_pData)
+    return true;
+
   if (IsEmpty())
     return other.IsEmpty();