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

include/llvm/MC/MCAsmInfo.h

@@ -217,6 +217,8 @@ namespace llvm {
     /// convention.
     bool HasMicrosoftFastStdCallMangling;    // Defaults to false.
 
+    bool NeedsDwarfSectionOffsetDirective;
+
     //===--- Alignment Information ----------------------------------------===//
 
     /// AlignDirective - The directive used to emit round up to an alignment
@@ -320,9 +322,6 @@ namespace llvm {
     /// encode inline subroutine information.
     bool DwarfUsesInlineInfoSection;         // Defaults to false.
 
-    /// DwarfSectionOffsetDirective - Special section offset directive.
-    const char* DwarfSectionOffsetDirective; // Defaults to NULL
-
     /// DwarfUsesRelocationsAcrossSections - True if Dwarf2 output generally
     /// uses relocations for references to other .debug_* sections.
     bool DwarfUsesRelocationsAcrossSections;
@@ -412,6 +411,10 @@ namespace llvm {
       return HasMicrosoftFastStdCallMangling;
     }
 
+    bool needsDwarfSectionOffsetDirective() const {
+      return NeedsDwarfSectionOffsetDirective;
+    }
+
     // Accessors.
     //
     bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
@@ -557,9 +560,6 @@ namespace llvm {
     bool doesDwarfUseInlineInfoSection() const {
       return DwarfUsesInlineInfoSection;
     }
-    const char *getDwarfSectionOffsetDirective() const {
-      return DwarfSectionOffsetDirective;
-    }
     bool doesDwarfUseRelocationsAcrossSections() const {
       return DwarfUsesRelocationsAcrossSections;
     }

lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp

@@ -141,7 +141,7 @@ void AsmPrinter::EmitTTypeReference(const GlobalValue *GV,
 void AsmPrinter::EmitSectionOffset(const MCSymbol *Label,
                                    const MCSymbol *SectionLabel) const {
   // On COFF targets, we have to emit the special .secrel32 directive.
-  if (MAI->getDwarfSectionOffsetDirective()) {
+  if (MAI->needsDwarfSectionOffsetDirective()) {
     OutStreamer.EmitCOFFSecRel32(Label);
     return;
   }

lib/MC/MCAsmInfo.cpp

@@ -87,10 +87,10 @@ MCAsmInfo::MCAsmInfo() {
   SupportsDebugInformation = false;
   ExceptionsType = ExceptionHandling::None;
   DwarfUsesInlineInfoSection = false;
-  DwarfSectionOffsetDirective = 0;
   DwarfUsesRelocationsAcrossSections = true;
   DwarfRegNumForCFI = false;
   HasMicrosoftFastStdCallMangling = false;
+  NeedsDwarfSectionOffsetDirective = false;
 }
 
 MCAsmInfo::~MCAsmInfo() {

lib/MC/MCAsmInfoCOFF.cpp

@@ -36,8 +36,8 @@ MCAsmInfoCOFF::MCAsmInfoCOFF() {
   // 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() { }

lib/Target/R600/MCTargetDesc/AMDGPUMCAsmInfo.cpp

@@ -68,8 +68,6 @@ AMDGPUMCAsmInfo::AMDGPUMCAsmInfo(const Target &T, StringRef &TT) : MCAsmInfo() {
   //===--- Dwarf Emission Directives -----------------------------------===//
   HasLEB128 = true;
   SupportsDebugInformation = true;
-  DwarfSectionOffsetDirective = ".offset";
-
 }
 
 const char*