Try to fix buildbot issues where some compilers can't auto move objects and most can.

[clayborg]

Failed to "arc diff" to update an older patch.

llvm/lib/DebugInfo/GSYM/GsymCreator.cpp

if (HeaderAndTableSize + SegmentFuncInfosSize >= SegmentSize) {
                                  "a segment size of %" PRIu64 " is to small to "
                                  "fit any function infos, specify a larger value",
                                  SegmentSize);
 
       break;
     }
     SegmentFuncInfosSize += alignTo(GC->copyFunctionInfo(*this, FuncIdx), 4);
   }
-  return GC;
+  return std::move(GC);
 }

llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp

static void AddFunctionInfo(GsymCreator &GC, const char *FuncName,
   Inline3.CallLine = 35;
   Inline3.Ranges.insert(AddressRange(FuncAddr + 0x16, FuncAddr + 0x18));
   FI.Inline->Children.emplace_back(Inline3);
   GC.addFunctionInfo(std::move(FI));
 }
 
 // Finalize a GsymCreator, encode it and decode it and return the error or
 // GsymReader that was successfully decoded.
-static Expected<GsymReader> FinalizeEncodeAndDecode(GsymCreator &GC) {
-  Error FinalizeErr = GC.finalize(llvm::nulls());
+static llvm::Expected<GsymReader> FinalizeEncodeAndDecode(GsymCreator &GC) {
+  llvm::Error FinalizeErr = GC.finalize(llvm::nulls());
   if (FinalizeErr)
-    return FinalizeErr;
+    return std::move(FinalizeErr);
   SmallString<1024> Str;
   raw_svector_ostream OutStrm(Str);
   const auto ByteOrder = support::endian::system_endianness();
   FileWriter FW(OutStrm, ByteOrder);
   llvm::Error Err = GC.encode(FW);
   if (Err)
-    return Err;
+    return std::move(Err);
   return GsymReader::copyBuffer(OutStrm.str());
 }
 
 TEST(GSYMTest, TestGsymSegmenting) {
   // Test creating a GSYM file with function infos and segment the information.
   // We verify segmenting is working by creating a full GSYM and also by
   // encoding multiple segments, then we verify that we get the same information
   // when doing lookups on the full GSYM that was decoded from encoding the