Use llvm:Twine instead of std::to_string.

[dblaikie]

Good to have a reason in the commit message/patch description - I assume
it's because std::to_string isn't available on some platforms? At least
that's what I recall seeing in previous patches.

[chaoren]

Add reason.

[ovyalov]

LGTM

llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h

processRelocationRef(unsigned SectionID, relocation_iterator RelI,
     UNIMPLEMENTED_RELOC(MachO::ARM_RELOC_SECTDIFF);
     UNIMPLEMENTED_RELOC(MachO::ARM_RELOC_LOCAL_SECTDIFF);
     UNIMPLEMENTED_RELOC(MachO::ARM_RELOC_PB_LA_PTR);
     UNIMPLEMENTED_RELOC(MachO::ARM_THUMB_RELOC_BR22);
     UNIMPLEMENTED_RELOC(MachO::ARM_THUMB_32BIT_BRANCH);
     UNIMPLEMENTED_RELOC(MachO::ARM_RELOC_HALF);
     default:
       if (RelType > MachO::ARM_RELOC_HALF_SECTDIFF)
-        return make_error<RuntimeDyldError>("MachO ARM relocation type " +
-                                            std::to_string(RelType) +
-                                            " is out of range");
+        return make_error<RuntimeDyldError>(("MachO ARM relocation type " +
+                                             Twine(RelType) +
+                                             " is out of range").str());
       break;
     }
 
     RelocationEntry RE(getRelocationEntry(SectionID, Obj, RelI));
     RE.Addend = decodeAddend(RE);
     RelocationValueRef Value;
     if (auto ValueOrErr = getRelocationValueRef(Obj, RelI, RE, ObjSectionToID))
       Value = *ValueOrErr;

llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h

processRelocationRef(unsigned SectionID, relocation_iterator RelI,
 
     if (Obj.isRelocationScattered(RelInfo)) {
       if (RelType == MachO::GENERIC_RELOC_SECTDIFF ||
           RelType == MachO::GENERIC_RELOC_LOCAL_SECTDIFF)
         return processSECTDIFFRelocation(SectionID, RelI, Obj,
                                          ObjSectionToID);
       else if (RelType == MachO::GENERIC_RELOC_VANILLA)
         return processScatteredVANILLA(SectionID, RelI, Obj, ObjSectionToID);
-      return make_error<RuntimeDyldError>("Unhandled I386 scattered relocation "
-                                          "type: " + std::to_string(RelType));
+      return make_error<RuntimeDyldError>(("Unhandled I386 scattered relocation "
+                                           "type: " + Twine(RelType)).str());
     }
 
     switch (RelType) {
     UNIMPLEMENTED_RELOC(MachO::GENERIC_RELOC_PAIR);
     UNIMPLEMENTED_RELOC(MachO::GENERIC_RELOC_PB_LA_PTR);
     UNIMPLEMENTED_RELOC(MachO::GENERIC_RELOC_TLV);
     default:
       if (RelType > MachO::GENERIC_RELOC_TLV)
-        return make_error<RuntimeDyldError>("MachO I386 relocation type " +
-                                            std::to_string(RelType) +
-                                            " is out of range");
+        return make_error<RuntimeDyldError>(("MachO I386 relocation type " +
+                                             Twine(RelType) +
+                                             " is out of range").str());
       break;
     }
 
     RelocationEntry RE(getRelocationEntry(SectionID, Obj, RelI));
     RE.Addend = memcpyAddend(RE);
     RelocationValueRef Value;
     if (auto ValueOrErr = getRelocationValueRef(Obj, RelI, RE, ObjSectionToID))
       Value = *ValueOrErr;

llvm/trunk/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOX86_64.h

processRelocationRef(unsigned SectionID, relocation_iterator RelI,
     bool IsExtern = Obj.getPlainRelocationExternal(RelInfo);
     if (!IsExtern && RE.IsPCRel)
       makeValueAddendPCRel(Value, RelI, 1 << RE.Size);
 
     switch (RelType) {
     UNIMPLEMENTED_RELOC(MachO::X86_64_RELOC_TLV);
     default:
       if (RelType > MachO::X86_64_RELOC_TLV)
-        return make_error<RuntimeDyldError>("MachO X86_64 relocation type " +
-                                            std::to_string(RelType) +
-                                            " is out of range");
+        return make_error<RuntimeDyldError>(("MachO X86_64 relocation type " +
+                                             Twine(RelType) +
+                                             " is out of range").str());
       break;
     }
 
     if (RE.RelType == MachO::X86_64_RELOC_GOT ||
         RE.RelType == MachO::X86_64_RELOC_GOT_LOAD)
       processGOTRelocation(RE, Value, Stubs);
     else {
       RE.Addend = Value.Offset;