Clarify the LSDASection NULL check

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124569 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DwarfException.cpp

@@ -451,6 +451,8 @@ void DwarfException::EmitExceptionTable() {
   }
 
   // Begin the exception table.
+  // Sometimes we want not to emit the data into separate section (e.g. ARM
+  // EHABI). In this case LSDASection will be NULL.
   if (LSDASection)
     Asm->OutStreamer.SwitchSection(LSDASection);
   Asm->EmitAlignment(2);