Test that evaluating target properties does not result in errors.
Merge topic 'test-genex-HEAD-target' into next

18c53b3 Test that evaluating target properties does not result in errors.
Revert "Genex: Fix the HEAD target used for evaluated expressions."

This reverts commit c6181fb6376481dd59423b84d08db571cf989661.
Merge topic 'fix-genex-HEAD-target' into next

2920c8b Revert "Genex: Fix the HEAD target used for evaluated expressions."
Revert "Use the same headTarget to evaluate linked content."

This reverts commit 4fab70449017394d92908f0cbd2b08ae0a50ecf7.
Revert "Genex: Fix the HEAD target used for evaluated expressions."

This reverts commit a53c6281905717b1e63aadf98ef34c699d3f9ff8.
Merge topic 'fix-genex-HEAD-target' into next

316b270 Revert "Genex: Fix the HEAD target used for evaluated expressions."
a53a5053 Revert "Use the same headTarget to evaluate linked content."
Genex: Fix the HEAD target used for evaluated expressions.

If the expression $<TARGET_PROPERTY:prop> appears in the content
of a target property, the target that prop is read from is
the 'head target' of the expression. In contexts such as evaluating
the content of a target property during generation, such
as INCLUDE_DIRECTORIES, the 'head target' is the one on which the
initial request was made.

If evaluating a generator expression which is not a target property
content, the target must be explicitly specified. Such contexts
include add_custom_command and file(GENERATE). The content might
then look like

 $<TARGET_PROPERTY:tgt,prop>

However, as there is no HeadTarget set, any generator expressions
evaluated as part of reading prop from tgt which do not specify
the tgt directly report an error.

Modify the logic of the TARGET_PROPERTY generator expression so
that in such contexts, the 'head target' is set to the appropriate
target which was first encountered.
Merge topic 'fix-genex-HEAD-target' into next

d1d4dac Genex: Fix the HEAD target used for evaluated expressions.