Add default initializers for WIN32_EXECUTABLE and MACOSX_BUNDLE

This allows downstreams to use

set(CMAKE_WIN32_EXECUTABLE ON)
set(CMAKE_MACOSX_BUNDLE ON)

to create executables with the WIN32_EXECUTABLE and MACOSX_BUNDLE
properties set on by default.

Source/cmDocumentVariables.cxx

@@ -1278,6 +1278,22 @@ void cmDocumentVariables::DefineVariables(cmake* cm)
      "See that target property for additional information.",
      false,
      "Variables that Control the Build");
+  cm->DefineProperty
+    ("CMAKE_WIN32_EXECUTABLE", cmProperty::VARIABLE,
+     "Default value for WIN32_EXECUTABLE of targets.",
+     "This variable is used to initialize the "
+     "WIN32_EXECUTABLE property on all the targets. "
+     "See that target property for additional information.",
+     false,
+     "Variables that Control the Build");
+  cm->DefineProperty
+    ("CMAKE_MACOSX_BUNDLE", cmProperty::VARIABLE,
+     "Default value for MACOSX_BUNDLE of targets.",
+     "This variable is used to initialize the "
+     "MACOSX_BUNDLE property on all the targets. "
+     "See that target property for additional information.",
+     false,
+     "Variables that Control the Build");
 
 //   Variables defined when the a language is enabled These variables will
 // also be defined whenever CMake has loaded its support for compiling (LANG)

Source/cmTarget.cxx

@@ -861,7 +861,9 @@ void cmTarget::DefineProperties(cmake *cm)
      "of of just main()."
      "This makes it a GUI executable instead of a console application.  "
      "See the CMAKE_MFC_FLAG variable documentation to configure use "
-     "of MFC for WinMain executables.");
+     "of MFC for WinMain executables.  "
+     "This property is initialized by the value of the variable "
+     "CMAKE_WIN32_EXECUTABLE if it is set when a target is created.");
 
   cm->DefineProperty
     ("MACOSX_BUNDLE", cmProperty::TARGET,
@@ -871,7 +873,9 @@ void cmTarget::DefineProperties(cmake *cm)
      "This makes it a GUI executable that can be launched from "
      "the Finder.  "
      "See the MACOSX_BUNDLE_INFO_PLIST target property for information "
-     "about creation of the Info.plist file for the application bundle.");
+     "about creation of the Info.plist file for the application bundle.  "
+     "This property is initialized by the value of the variable "
+     "CMAKE_MACOSX_BUNDLE if it is set when a target is created.");
 
   cm->DefineProperty
     ("MACOSX_BUNDLE_INFO_PLIST", cmProperty::TARGET,
@@ -1224,6 +1228,8 @@ void cmTarget::SetMakefile(cmMakefile* mf)
   this->SetPropertyDefault("AUTOMOC", 0);
   this->SetPropertyDefault("AUTOMOC_MOC_OPTIONS", 0);
   this->SetPropertyDefault("LINK_INTERFACE_LIBRARIES", 0);
+  this->SetPropertyDefault("WIN32_EXECUTABLE", 0);
+  this->SetPropertyDefault("MACOSX_BUNDLE", 0);
 
   // Collect the set of configuration types.
   std::vector<std::string> configNames;