[Capability System] Fix bug where capabilities do not correctly propegate if AST-parent has target+set the AST-child does not (#8175)

Fixes: #8174

Changes:
* To determine if we propagate capabilities, we need to ensure that a
`join` will do nothing (optimization since `join` is expensive + caching
data for the `join` adds up to be expensive). This logic was changed in
`slang-check-decl.cpp` since the current logic was incorrect.
* A parent could have the set `metal+glsl` and the use-site could have
`glsl`. In this case, we will not remove `metal` from the parent since
`{metal+glsl}.implies({glsl})` is true.

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Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

0 files changed, 0 insertions, 0 deletions