[ELF] Linkerscript: define symbols outside SECTIONS

Symbol assignments outside of SECTIONS command need to be created
even when SECTIONS command is not used.

Differential Revision: https://reviews.llvm.org/D23751

llvm-svn: 280252
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index a3c59d4..3475de8 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -249,6 +249,8 @@
   CommonInputSection<ELFT> Common(getCommonSymbols<ELFT>());
   CommonInputSection<ELFT>::X = &Common;
 
+  Script<ELFT>::X->createAssignments();
+
   Script<ELFT>::X->OutputSections = &OutputSections;
   if (ScriptConfig->HasContents)
     Script<ELFT>::X->createSections(Factory);