Minor fix for autocreated object repeated fields and maps.

- If setting/clearing a repeated field/map that was objects, check the class
  before checking the autocreator.
- Just to be paranoid, don’t mutate within copy/mutableCopy for the autocreated
  classes to ensure there is less chance of issues if someone does something
  really crazy threading wise.
- Some more tests for the internal AutocreatedArray/AutocreatedDictionary
  classes to ensure things are working as expected.
- Add Xcode 8.2 to the full_mac_build.sh supported list.
diff --git a/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj b/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj
index 5f59971..64fc45c 100644
--- a/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj
+++ b/objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj
@@ -65,6 +65,7 @@
 		F47476E91D21A537007C7B1A /* Duration.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B4248DE1A929C7D00BC1EC6 /* Duration.pbobjc.m */; };
 		F47476EA1D21A537007C7B1A /* Timestamp.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B4248E01A929C7D00BC1EC6 /* Timestamp.pbobjc.m */; };
 		F4B51B1C1BBC5C7100744318 /* GPBObjectiveCPlusPlusTest.mm in Sources */ = {isa = PBXBuildFile; fileRef = F4B51B1B1BBC5C7100744318 /* GPBObjectiveCPlusPlusTest.mm */; };
+		F4C4B9E71E1D97BF00D3B61D /* GPBDictionaryTests.m in Sources */ = {isa = PBXBuildFile; fileRef = F4C4B9E51E1D97BB00D3B61D /* GPBDictionaryTests.m */; };
 		F4E675D01B21D1620054530B /* Any.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = F4E675B71B21D1440054530B /* Any.pbobjc.m */; };
 		F4E675D11B21D1620054530B /* Api.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = F4E675B91B21D1440054530B /* Api.pbobjc.m */; };
 		F4E675D21B21D1620054530B /* Empty.pbobjc.m in Sources */ = {isa = PBXBuildFile; fileRef = F4E675BC1B21D1440054530B /* Empty.pbobjc.m */; };
@@ -209,6 +210,7 @@
 		F4B6B8B11A9CCBBB00892426 /* GPBUnknownFieldSet_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBUnknownFieldSet_PackagePrivate.h; sourceTree = "<group>"; };
 		F4B6B8B31A9CD1C600892426 /* GPBExtensionInternals.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBExtensionInternals.h; sourceTree = "<group>"; };
 		F4B6B8B51A9CD1C600892426 /* GPBRootObject_PackagePrivate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GPBRootObject_PackagePrivate.h; sourceTree = "<group>"; };
+		F4C4B9E51E1D97BB00D3B61D /* GPBDictionaryTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GPBDictionaryTests.m; sourceTree = "<group>"; };
 		F4CF31711B162EF500BD9B06 /* unittest_objc_startup.proto */ = {isa = PBXFileReference; lastKnownFileType = text; path = unittest_objc_startup.proto; sourceTree = "<group>"; };
 		F4E675B61B21D1440054530B /* Any.pbobjc.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; name = Any.pbobjc.h; path = google/protobuf/Any.pbobjc.h; sourceTree = "<group>"; };
 		F4E675B71B21D1440054530B /* Any.pbobjc.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; name = Any.pbobjc.m; path = google/protobuf/Any.pbobjc.m; sourceTree = "<group>"; };
@@ -431,6 +433,7 @@
 				7461B69D0F94FDF800A0C422 /* GPBCodedOuputStreamTests.m */,
 				5102DABB1891A052002037B6 /* GPBConcurrencyTests.m */,
 				F4353D1E1AB88243005A6198 /* GPBDescriptorTests.m */,
+				F4C4B9E51E1D97BB00D3B61D /* GPBDictionaryTests.m */,
 				F4353D3A1AC06F31005A6198 /* GPBDictionaryTests.pddm */,
 				F4353D3B1AC06F31005A6198 /* GPBDictionaryTests+Bool.m */,
 				F4353D3C1AC06F31005A6198 /* GPBDictionaryTests+Int32.m */,
@@ -773,6 +776,7 @@
 				F4353D451AC06F31005A6198 /* GPBDictionaryTests+String.m in Sources */,
 				F4353D461AC06F31005A6198 /* GPBDictionaryTests+UInt32.m in Sources */,
 				8BBEA4B7147C727D00C4ADB7 /* GPBUtilitiesTests.m in Sources */,
+				F4C4B9E71E1D97BF00D3B61D /* GPBDictionaryTests.m in Sources */,
 				8BBEA4B8147C727D00C4ADB7 /* GPBWireFormatTests.m in Sources */,
 				8BD3981F14BE59D70081D629 /* GPBUnittestProtos.m in Sources */,
 				8B8B615D17DF7056002EE618 /* GPBARCUnittestProtos.m in Sources */,