Disable implicit dependency finding and parallelized builds for XCTest schemes

This is an attempt to resolve intermittent build failures that have the
appearance of being caused by a race condition.

Author: briancroom

XCTest.xcodeproj/xcshareddata/xcschemes/SwiftXCTest.xcscheme

@@ -3,9 +3,23 @@
    LastUpgradeVersion = "0720"
    version = "1.3">
    <BuildAction
-      parallelizeBuildables = "YES"
-      buildImplicitDependencies = "YES">
+      parallelizeBuildables = "NO"
+      buildImplicitDependencies = "NO">
       <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "5B5D885C1BBC938800234F36"
+               BuildableName = "SwiftFoundation.framework"
+               BlueprintName = "SwiftFoundation"
+               ReferencedContainer = "container:../swift-corelibs-foundation/Foundation.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
          <BuildActionEntry
             buildForTesting = "YES"
             buildForRunning = "YES"
@@ -29,6 +43,15 @@
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
       </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "5B5D86DA1BBC74AD00234F36"
+            BuildableName = "SwiftXCTest.framework"
+            BlueprintName = "SwiftXCTest"
+            ReferencedContainer = "container:XCTest.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
       <AdditionalOptions>
       </AdditionalOptions>
    </TestAction>

XCTest.xcodeproj/xcshareddata/xcschemes/SwiftXCTestFunctionalTests.xcscheme

@@ -3,9 +3,37 @@
    LastUpgradeVersion = "0720"
    version = "1.3">
    <BuildAction
-      parallelizeBuildables = "YES"
-      buildImplicitDependencies = "YES">
+      parallelizeBuildables = "NO"
+      buildImplicitDependencies = "NO">
       <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "5B5D885C1BBC938800234F36"
+               BuildableName = "SwiftFoundation.framework"
+               BlueprintName = "SwiftFoundation"
+               ReferencedContainer = "container:../swift-corelibs-foundation/Foundation.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "5B5D86DA1BBC74AD00234F36"
+               BuildableName = "SwiftXCTest.framework"
+               BlueprintName = "SwiftXCTest"
+               ReferencedContainer = "container:XCTest.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
          <BuildActionEntry
             buildForTesting = "YES"
             buildForRunning = "YES"
@@ -29,6 +57,15 @@
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
       </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "DAA333B51C267AD6000CC115"
+            BuildableName = "SwiftXCTestFunctionalTests"
+            BlueprintName = "SwiftXCTestFunctionalTests"
+            ReferencedContainer = "container:XCTest.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
       <AdditionalOptions>
       </AdditionalOptions>
    </TestAction>