Merge topic 'xcode-12-legacy-deprecation'

36fc3a1e84 Xcode: Suppress legacy build system deprecation warning

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !5052
diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index e54de5d..f632257 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -3753,6 +3753,8 @@
   if (this->XcodeVersion >= 100) {
     xout.Element("key", "BuildSystemType");
     xout.Element("string", "Original");
+    xout.Element("key", "DisableBuildSystemDeprecationWarning");
+    xout.Element("true");
   }
   if (hasGeneratedSchemes) {
     xout.Element("key",