VS: Generate a custom command only in the least dependent target

If a custom command is assigned to multiple targets, generate the build
rule only in the least-dependent `.vcxproj` file.  Otherwise MSBuild
will run the command on the first build of a dependent target even if
its dependencies already brought the command up to date (in order to
populates its build log).

Generate targets in least-to-most-dependent order, and assign a custom
command to the least dependent target.

Added cmLocalVisualStudio10Generator::GenerateTargetsDepthFirst to call
cmVisualStudio10TargetGenerator::Generate in least-dependent order.

Moved SourcesVisited from cmVisualStudio10TargetGenerator to
cmLocalVisualStudio10Generator to avoid attaching a custom command to
multiple targets among the local generator.

Fixes: #16767

1 files changed, 3 insertions, 0 deletions

diff --git a/Tests/RunCMake/add_custom_command/a.c b/Tests/RunCMake/add_custom_command/a.c
new file mode 100644
index 0000000..707c1c3
--- /dev/null
+++ b/Tests/RunCMake/add_custom_command/a.c
@@ -0,0 +1,3 @@
+void a()
+{
+}