Drop the performace baselines.

We weren't really using them, and the nested path causes checkout problems
on windows.

objectivec/ProtocolBuffers_iOS.xcodeproj/xcshareddata/xcbaselines/8BBEA4A5147C727100C4ADB7.xcbaseline/FFE465CA-0E74-40E8-9F09-500B66B7DCB2.plist

-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-	<key>classNames</key>
-	<dict>
-		<key>PerfTests</key>
-		<dict>
-			<key>testExtensionsPerformance</key>
-			<dict>
-				<key>com.apple.XCTPerformanceMetric_WallClockTime</key>
-				<dict>
-					<key>baselineAverage</key>
-					<real>0.9</real>
-					<key>baselineIntegrationDisplayName</key>
-					<string>Feb 5, 2015, 9:42:41 AM</string>
-				</dict>
-			</dict>
-			<key>testHas</key>
-			<dict>
-				<key>com.apple.XCTPerformanceMetric_WallClockTime</key>
-				<dict>
-					<key>baselineAverage</key>
-					<real>0.09</real>
-					<key>baselineIntegrationDisplayName</key>
-					<string>Feb 5, 2015, 9:42:35 AM</string>
-				</dict>
-			</dict>
-			<key>testMessagePerformance</key>
-			<dict>
-				<key>com.apple.XCTPerformanceMetric_WallClockTime</key>
-				<dict>
-					<key>baselineAverage</key>
-					<real>0.57</real>
-					<key>baselineIntegrationDisplayName</key>
-					<string>Feb 5, 2015, 9:42:47 AM</string>
-				</dict>
-			</dict>
-			<key>testPackedExtensionsPerformance</key>
-			<dict>
-				<key>com.apple.XCTPerformanceMetric_WallClockTime</key>
-				<dict>
-					<key>baselineAverage</key>
-					<real>0.75</real>
-					<key>baselineIntegrationDisplayName</key>
-					<string>Feb 5, 2015, 9:42:51 AM</string>
-				</dict>
-			</dict>
-			<key>testPackedTypesPerformance</key>
-			<dict>
-				<key>com.apple.XCTPerformanceMetric_WallClockTime</key>
-				<dict>
-					<key>baselineAverage</key>
-					<real>0.26</real>
-					<key>baselineIntegrationDisplayName</key>
-					<string>Feb 5, 2015, 9:42:55 AM</string>
-				</dict>
-			</dict>
-		</dict>
-	</dict>
-</dict>
-</plist>

objectivec/ProtocolBuffers_iOS.xcodeproj/xcshareddata/xcbaselines/8BBEA4A5147C727100C4ADB7.xcbaseline/Info.plist

-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-	<key>runDestinationsByUUID</key>
-	<dict>
-		<key>FFE465CA-0E74-40E8-9F09-500B66B7DCB2</key>
-		<dict>
-			<key>targetArchitecture</key>
-			<string>arm64</string>
-			<key>targetDevice</key>
-			<dict>
-				<key>modelCode</key>
-				<string>iPhone7,1</string>
-				<key>platformIdentifier</key>
-				<string>com.apple.platform.iphoneos</string>
-			</dict>
-		</dict>
-	</dict>
-</dict>
-</plist>