Add new _getName to get extension decl names for core module docs (#7985)

Fixes #7479

This adds a new variant of `_getName(ExtensionDecl* decl)` to our
markdown doc writer that takes an ExtensionDecl* and returns the name in
the format `extension <name> : <interface>`.

This is required to display "extension T : ITexelElement" properly in
the core module docs, as the existing `_getName(Decl* decl)` returns an
empty string because the name does not come from the `decl` itself, but
rather its `targetType`.

The target type alone is not enough, as that would return `T`, which
will be erroneously interpreted as the name for the generic parameter,
and the doc system will link every mention of `T` to the extension's
page.

ReadTheDocs already displays the name correctly in the TOC of the docs
there, but that is because it falls back to the page title when the name
in the TOC is empty.

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

0 files changed, 0 insertions, 0 deletions