[LLD][ELF] Fix stale comments about doing ICF

Differential Revision: https://reviews.llvm.org/D68396

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@374362 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/ELF/Driver.cpp b/ELF/Driver.cpp
index 616718b..96257a4 100644
--- a/ELF/Driver.cpp
+++ b/ELF/Driver.cpp
@@ -1915,9 +1915,10 @@
   // Replace common symbols with regular symbols.
   replaceCommonSymbols();
 
-  // Do size optimizations: garbage collection, merging of SHF_MERGE sections
-  // and identical code folding.
+  // Split SHF_MERGE and .eh_frame sections into pieces in preparation for garbage collection.
   splitSections<ELFT>();
+
+  // Garbage collection and removal of shared symbols from unused shared objects.
   markLive<ELFT>();
   demoteSharedSymbols();