CMake Nightly Date Stamp
Fix include dir propagation from conditionally linked targets

Code like

 target_link_libraries(B debug A)

generates usage requirement references such as "$<$<CONFIG:DEBUG>:A>".
When cmTarget::GetIncludeDirectories uses such references it generates
expressions like:

 $<TARGET_PROPERTY:$<$<CONFIG:DEBUG>:A>,INTERFACE_INCLUDE_DIRECTORIES>

When the conditions are false such references evaluate as an empty
string and the expression fails with an error such as:

 $<TARGET_PROPERTY:tgt,prop> expression requires a non-empty target name.

Fix this by teaching cmTarget::GetIncludeDirectories to wrap the above
expression inside a conditional:

 $<$<BOOL:$<$<CONFIG:DEBUG>:A>>:...>

so that $<TARGET_PROPERTY:...> will not be evaluated with an empty
target.
Merge topic 'fix-per-config-tll-include-dirs' into next

de9d4a6 Fix include dir propagation from conditionally linked targets
78185f5 CMake Nightly Date Stamp