Handle multiple .tbss sections.

llvm-svn: 282147
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index a8ed925..7edfaca 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -373,7 +373,9 @@
   // .foo { *(.aaa) a = SIZEOF(.foo); *(.bbb) }
   CurOutSec->setSize(Pos - CurOutSec->getVA());
 
-  if (!IsTbss)
+  if (IsTbss)
+    ThreadBssOffset = Pos - Dot;
+  else
     Dot = Pos;
 }