Index: include/llvm/CodeGen/AccelTable.h
===================================================================
--- include/llvm/CodeGen/AccelTable.h
+++ include/llvm/CodeGen/AccelTable.h
@@ -129,9 +129,9 @@
   /// specification of the form of its data.
   struct Atom {
     /// Atom Type.
-    const uint16_t Type;
+    uint16_t Type;
     /// DWARF Form.
-    const uint16_t Form;
+    uint16_t Form;
 
     constexpr Atom(uint16_t Type, uint16_t Form) : Type(Type), Form(Form) {}
 
@@ -153,10 +153,10 @@
     /// base is used to describe the offset for all forms in the list of atoms.
     uint32_t DieOffsetBase;
 
-    SmallVector<Atom, 3> Atoms;
+    const SmallVector<Atom, 4> Atoms;
 
-    HeaderData(ArrayRef<Atom> AtomList, uint32_t Offset = 0)
-        : DieOffsetBase(Offset), Atoms(AtomList.begin(), AtomList.end()) {}
+    HeaderData(const SmallVectorImpl<Atom> &Atoms, uint32_t Offset = 0)
+        : DieOffsetBase(Offset), Atoms(Atoms.begin(), Atoms.end()) {}
 
 #ifndef NDEBUG
     void print(raw_ostream &OS) const {
@@ -174,7 +174,7 @@
 
 public:
   /// The length of the header data is always going to be 4 + 4 + 4*NumAtoms.
-  AppleAccelTableHeader(ArrayRef<AppleAccelTableHeader::Atom> Atoms)
+  AppleAccelTableHeader(const SmallVectorImpl<Atom> &Atoms)
       : Header(8 + (Atoms.size() * 4)), HeaderData(Atoms) {}
 
   /// Update header with hash and bucket count.
@@ -270,7 +270,7 @@
   using BucketList = std::vector<HashList>;
   BucketList Buckets;
 
-  AppleAccelTableBase(ArrayRef<AppleAccelTableHeader::Atom> Atoms)
+  AppleAccelTableBase(const SmallVectorImpl<AppleAccelTableHeader::Atom> &Atoms)
       : Header(Atoms), Entries(Allocator) {}
 
 private:
@@ -368,9 +368,7 @@
 
   void emit(AsmPrinter *Asm) const override;
 
-  static constexpr const AppleAccelTableHeader::Atom Atoms[] = {
-      AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_offset,
-                                  dwarf::DW_FORM_data4)};
+  static const SmallVector<AppleAccelTableHeader::Atom, 4> Atoms;
 
 #ifndef NDEBUG
   void print(raw_ostream &OS) const override {
@@ -391,12 +389,7 @@
 
   void emit(AsmPrinter *Asm) const override;
 
-  static constexpr const AppleAccelTableHeader::Atom Atoms[] = {
-      AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_offset,
-                                  dwarf::DW_FORM_data4),
-      AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
-      AppleAccelTableHeader::Atom(dwarf::DW_ATOM_type_flags,
-                                  dwarf::DW_FORM_data1)};
+  static const SmallVector<AppleAccelTableHeader::Atom, 4> Atoms;
 
 #ifndef NDEBUG
   void print(raw_ostream &OS) const override {
@@ -414,9 +407,7 @@
 
   void emit(AsmPrinter *Asm) const override;
 
-  static constexpr const AppleAccelTableHeader::Atom Atoms[] = {
-      AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_offset,
-                                  dwarf::DW_FORM_data4)};
+  static const SmallVector<AppleAccelTableHeader::Atom, 4> Atoms;
 
 #ifndef NDEBUG
   void print(raw_ostream &OS) const override {
@@ -443,12 +434,7 @@
 
   void emit(AsmPrinter *Asm) const override;
 
-  static constexpr const AppleAccelTableHeader::Atom Atoms[] = {
-      AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_offset,
-                                  dwarf::DW_FORM_data4),
-      AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
-      AppleAccelTableHeader::Atom(5, dwarf::DW_FORM_data1),
-      AppleAccelTableHeader::Atom(6, dwarf::DW_FORM_data4)};
+  static const SmallVector<AppleAccelTableHeader::Atom, 4> Atoms;
 
 #ifndef NDEBUG
   void print(raw_ostream &OS) const override {
Index: lib/CodeGen/AsmPrinter/AccelTable.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AccelTable.cpp
+++ lib/CodeGen/AsmPrinter/AccelTable.cpp
@@ -70,11 +70,6 @@
   Header.HashCount = HashCount;
 }
 
-constexpr const AppleAccelTableHeader::Atom AppleAccelTableTypeData::Atoms[];
-constexpr const AppleAccelTableHeader::Atom AppleAccelTableOffsetData::Atoms[];
-constexpr const AppleAccelTableHeader::Atom AppleAccelTableStaticOffsetData::Atoms[];
-constexpr const AppleAccelTableHeader::Atom AppleAccelTableStaticTypeData::Atoms[];
-
 void AppleAccelTableBase::emitHeader(AsmPrinter *Asm) { Header.emit(Asm); }
 
 void AppleAccelTableBase::emitBuckets(AsmPrinter *Asm) {
@@ -233,3 +228,29 @@
                                           : 0);
   Asm->EmitInt32(QualifiedNameHash);
 }
+
+const SmallVector<AppleAccelTableHeader::Atom, 4>
+    AppleAccelTableOffsetData::Atoms = {AppleAccelTableHeader::Atom(
+        dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4)};
+
+const SmallVector<AppleAccelTableHeader::Atom, 4>
+    AppleAccelTableTypeData::Atoms = {
+        AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_offset,
+                                    dwarf::DW_FORM_data4),
+        AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_tag,
+                                    dwarf::DW_FORM_data2),
+        AppleAccelTableHeader::Atom(dwarf::DW_ATOM_type_flags,
+                                    dwarf::DW_FORM_data1)};
+
+const SmallVector<AppleAccelTableHeader::Atom, 4>
+    AppleAccelTableStaticOffsetData::Atoms = {AppleAccelTableHeader::Atom(
+        dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4)};
+
+const SmallVector<AppleAccelTableHeader::Atom, 4>
+    AppleAccelTableStaticTypeData::Atoms = {
+        AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_offset,
+                                    dwarf::DW_FORM_data4),
+        AppleAccelTableHeader::Atom(dwarf::DW_ATOM_die_tag,
+                                    dwarf::DW_FORM_data2),
+        AppleAccelTableHeader::Atom(5, dwarf::DW_FORM_data1),
+        AppleAccelTableHeader::Atom(6, dwarf::DW_FORM_data4)};