Add more DWARF 5 language constants.

[echristo]

Hi Bruce,

The DWARF5 standard hasn't been released yet and so the numbers aren't
technically final yet so I've been avoiding making those changes if
possible. Mind holding off a couple weeks until (I hope) the preliminary
review copy is released?

Thanks!

-eric

[echristo]

After discussion on the lldb bug I've been convinced that we can label these as "subject to change" but allow people to get testing going.

LGTM.

-eric

[brucem]

Update for recent changes on HEAD.

[echristo]

LGTM still. Thanks!

-eric

include/llvm/Support/Dwarf.h

enum SourceLanguage {
   DW_LANG_Python = 0x0014,
   DW_LANG_OpenCL = 0x0015,
   DW_LANG_Go = 0x0016,
   DW_LANG_Modula3 = 0x0017,
   DW_LANG_Haskell = 0x0018,
   DW_LANG_C_plus_plus_03 = 0x0019,
   DW_LANG_C_plus_plus_11 = 0x001a,
   DW_LANG_OCaml = 0x001b,
+  DW_LANG_Rust = 0x001c,
+  DW_LANG_C11 = 0x001d,
+  DW_LANG_Swift = 0x001e,
+  DW_LANG_Julia = 0x001f,
+  DW_LANG_Dylan = 0x0020,
+  DW_LANG_C_plus_plus_14 = 0x0021,
+  DW_LANG_Fortran03 = 0x0022,
+  DW_LANG_Fortran08 = 0x0023,
 
   DW_LANG_lo_user = 0x8000,
   DW_LANG_Mips_Assembler = 0x8001,
   DW_LANG_hi_user = 0xffff
 };
 
 enum CaseSensitivity {
   // Identifier case codes

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

int64_t DwarfUnit::getDefaultLowerBound() const {
   case dwarf::DW_LANG_Cobol74:
   case dwarf::DW_LANG_Cobol85:
   case dwarf::DW_LANG_Modula2:
   case dwarf::DW_LANG_Pascal83:
   case dwarf::DW_LANG_PLI:
     if (dwarf::DWARF_VERSION >= 4)
       return 1;
     break;
+
+  // The languages below have valid values only if the DWARF version >= 5.
+  case dwarf::DW_LANG_OpenCL:
+  case dwarf::DW_LANG_Go:
+  case dwarf::DW_LANG_Haskell:
+  case dwarf::DW_LANG_C_plus_plus_03:
+  case dwarf::DW_LANG_C_plus_plus_11:
+  case dwarf::DW_LANG_OCaml:
+  case dwarf::DW_LANG_Rust:
+  case dwarf::DW_LANG_C11:
+  case dwarf::DW_LANG_Swift:
+  case dwarf::DW_LANG_Dylan:
+  case dwarf::DW_LANG_C_plus_plus_14:
+    if (dwarf::DWARF_VERSION >= 5)
+      return 0;
+    break;
+
+  case dwarf::DW_LANG_Modula3:
+  case dwarf::DW_LANG_Julia:
+  case dwarf::DW_LANG_Fortran03:
+  case dwarf::DW_LANG_Fortran08:
+    if (dwarf::DWARF_VERSION >= 5)
+      return 1;
+    break;
   }
 
   return -1;
 }
 
 /// Check whether the DIE for this MDNode can be shared across CUs.
 static bool isShareableAcrossCUs(DIDescriptor D) {
   // When the MDNode can be part of the type system, the DIE can be shared

lib/IR/DIBuilder.cpp

 DICompileUnit DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
                                            StringRef Directory,
                                            StringRef Producer, bool isOptimized,
                                            StringRef Flags, unsigned RunTimeVer,
                                            StringRef SplitName,
                                            DebugEmissionKind Kind,
                                            bool EmitDebugInfo) {
 
-  assert(((Lang <= dwarf::DW_LANG_OCaml && Lang >= dwarf::DW_LANG_C89) ||
+  assert(((Lang <= dwarf::DW_LANG_Fortran08 && Lang >= dwarf::DW_LANG_C89) ||
           (Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
          "Invalid Language tag");
   assert(!Filename.empty() &&
          "Unable to create compile unit without filename");
   Metadata *TElts[] = {HeaderBuilder::get(DW_TAG_base_type).get(VMContext)};
   TempEnumTypes = MDNode::getTemporary(VMContext, TElts).release();
 
   TempRetainTypes = MDNode::getTemporary(VMContext, TElts).release();

lib/Support/Dwarf.cpp

const char *llvm::dwarf::LanguageString(unsigned Language) {
   case DW_LANG_Python:                   return "DW_LANG_Python";
   case DW_LANG_OpenCL:                   return "DW_LANG_OpenCL";
   case DW_LANG_Go:                       return "DW_LANG_Go";
   case DW_LANG_Modula3:                  return "DW_LANG_Modula3";
   case DW_LANG_Haskell:                  return "DW_LANG_Haskell";
   case DW_LANG_C_plus_plus_03:           return "DW_LANG_C_plus_plus_03";
   case DW_LANG_C_plus_plus_11:           return "DW_LANG_C_plus_plus_11";
   case DW_LANG_OCaml:                    return "DW_LANG_OCaml";
+  case DW_LANG_Rust:                     return "DW_LANG_Rust";
+  case DW_LANG_C11:                      return "DW_LANG_C11";
+  case DW_LANG_Swift:                    return "DW_LANG_Swift";
+  case DW_LANG_Julia:                    return "DW_LANG_Julia";
+  case DW_LANG_Dylan:                    return "DW_LANG_Dylan";
+  case DW_LANG_C_plus_plus_14:           return "DW_LANG_C_plus_plus_14";
+  case DW_LANG_Fortran03:                return "DW_LANG_Fortran03";
+  case DW_LANG_Fortran08:                return "DW_LANG_Fortran08";
+
   case DW_LANG_lo_user:                  return "DW_LANG_lo_user";
   case DW_LANG_Mips_Assembler:           return "DW_LANG_Mips_Assembler";
   case DW_LANG_hi_user:                  return "DW_LANG_hi_user";
   }
   return nullptr;
 }
 
 const char *llvm::dwarf::CaseString(unsigned Case) {