Merge topic 'xcode-build-layout'

d0a6ebf57b Xcode: Fix "clean" operation under the "new build system"
dc5fc898f6 Xcode: Set object file locations using TARGET_TEMP_DIR
a7fb4bc475 Xcode: Set build product locations using CONFIGURATION_BUILD_DIR
6883b82124 cmGlobalXCodeGenerator: Remove unused local variable settings

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !7730