Move ELF to HasReliableSymbolDifference=true. Also take the opportunity to put
symbols defined in merge sections in independent atoms.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114786 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86AsmBackend.cpp b/lib/Target/X86/X86AsmBackend.cpp
index 4b51b69..231f151 100644
--- a/lib/Target/X86/X86AsmBackend.cpp
+++ b/lib/Target/X86/X86AsmBackend.cpp
@@ -191,6 +191,12 @@
     : X86AsmBackend(T), OSType(_OSType) {
     HasAbsolutizedSet = true;
     HasScatteredSymbols = true;
+    HasReliableSymbolDifference = true;
+  }
+
+  virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
+    const MCSectionELF &ES = static_cast<const MCSectionELF&>(Section);
+    return ES.getFlags() & MCSectionELF::SHF_MERGE;
   }
 
   bool isVirtualSection(const MCSection &Section) const {