cmTarget: Remove some hardcoding of transitive property names.
GenexEval: Extract a getLinkedTargetsContent from TargetPropertyNode.

This will be used to process transitive components of properties
which depend on linked targets. Currently only the link interface
of the target can be used as the source of the linked targets, but
in the next commit it will be possible to use the link implementation
as the source of link targets.

This commit does not change the semantics of the code.
GenexEval: Fix evaluation of INCLUDE_DIRECTORIES target property.

This property should come from the content of the property itself,
plus the INTERFACE_INCLUDE_DIRECTORIES of the link *implementation*.

In contrast, when the INTERFACE_INCLUDE_DIRECTORIES is evaluated for
a target, the INTERFACE_INCLUDE_DIRECTORIES of the link *interface*
is used.

Similar logic applies for the COMPILE_DEFINITIONS target properties.

If the propertyName is already an INTERFACE_ variant of the property,
ie, the expression is similar to

 $<TARGET_PROPERTY:foo,INTERFACE_INCLUDE_DIRECTORIES>

then the INTERFACE_INCLUDE_DIRECTORIES of the link *interface* of foo
is used.

However, if the propertyName is not an INTERFACE_ variant, and the
interfacePropertyName is, ie, the expression is similar to:

 $<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>

then the INTERFACE_INCLUDE_DIRECTORIES of the link *implementation*
of foo is used.
Revert the target-COMPILE_OPTIONS topic.

This is temporary to resolve conflicts with another topic.
Revert the fix-INCLUDE_DIRECTORIES-genex-read topic.
Merge topic 'fix-INCLUDE_DIRECTORIES-genex-read' into next

aeff2c5 Revert the fix-INCLUDE_DIRECTORIES-genex-read topic.
Merge topic 'target-COMPILE_OPTIONS' into next

83eef55 Revert the target-COMPILE_OPTIONS topic.
Merge topic 'fix-INCLUDE_DIRECTORIES-genex-read' into next

3aa9ce4 GenexEval: Fix evaluation of INCLUDE_DIRECTORIES target property.
0b39fef GenexEval: Extract a getLinkedTargetsContent from TargetPropertyNode.
53164ac cmTarget: Remove some hardcoding of transitive property names.