Reduce diff ref/pref keys

Author: bhargavg

Sources/Xcodeproj/Module+PBXProj.swift

@@ -27,17 +27,17 @@ import struct Utility.Toolchain
 import struct Utility.Path
 import PackageType
 
-let rootObjectReference =                           "____RootObject_"
-let rootBuildConfigurationListReference =           "_____RootConfs_"
-let rootBuildConfigurationReference =               "_________Debug_"
-let rootGroupReference =                            "_____RootGroup_"
-let productsGroupReference =                        "______Products_"
-let sourcesGroupReference =                         "_______Sources_"
-let dependenciesGroupReference =                    "__Dependencies_"
-let testsGroupReference =                           "_________Tests_"
-let linkPhaseFileRefPrefix =                        "___LinkFileRef_"
-let sourceGroupFileRefPrefix =                      "____PBXFileRef_"
-let compilePhaseFileRefPrefix =                     "____src_cc_ref_"
+let rootObjectReference =                           "__RootObject_"
+let rootBuildConfigurationListReference =           "___RootConfs_"
+let rootBuildConfigurationReference =               "_______Debug_"
+let rootGroupReference =                            "___RootGroup_"
+let productsGroupReference =                        "____Products_"
+let sourcesGroupReference =                         "_____Sources_"
+let dependenciesGroupReference =                    "Dependencies_"
+let testsGroupReference =                           "_______Tests_"
+let linkPhaseFileRefPrefix =                        "_LinkFileRef_"
+let sourceGroupFileRefPrefix =                      "__PBXFileRef_"
+let compilePhaseFileRefPrefix =                     "__src_cc_ref_"
 
 extension Module {
     var dependencyReference: String        { return "__Dependency_\(c99name)" }