Remove unused DwarfSectionOffsetDirective string

The value isn't actually used, and setting it emits a COFF specific
directive.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180064 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAsmInfo.cpp b/lib/MC/MCAsmInfo.cpp
index 51bb435..9e60884 100644
--- a/lib/MC/MCAsmInfo.cpp
+++ b/lib/MC/MCAsmInfo.cpp
@@ -87,10 +87,10 @@
   SupportsDebugInformation = false;
   ExceptionsType = ExceptionHandling::None;
   DwarfUsesInlineInfoSection = false;
-  DwarfSectionOffsetDirective = 0;
   DwarfUsesRelocationsAcrossSections = true;
   DwarfRegNumForCFI = false;
   HasMicrosoftFastStdCallMangling = false;
+  NeedsDwarfSectionOffsetDirective = false;
 }
 
 MCAsmInfo::~MCAsmInfo() {
diff --git a/lib/MC/MCAsmInfoCOFF.cpp b/lib/MC/MCAsmInfoCOFF.cpp
index fd79193..33350d9 100644
--- a/lib/MC/MCAsmInfoCOFF.cpp
+++ b/lib/MC/MCAsmInfoCOFF.cpp
@@ -36,8 +36,8 @@
   // Set up DWARF directives
   HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
   SupportsDebugInformation = true;
-  DwarfSectionOffsetDirective = "\t.secrel32\t";
   HasMicrosoftFastStdCallMangling = true;
+  NeedsDwarfSectionOffsetDirective = true;
 }
 
 void MCAsmInfoMicrosoft::anchor() { }