fixes#24186
When encountering pragma nodes in templates, if it's a language pragma,
we don't process the name, and only any values if they exist. If it's
not a language pragma, we process the full node. Previously only the
values of colon expressions were processed.
To make this simpler, `whichPragma` is patched to consider bracketed
hint/warning etc pragmas like `{.hint[HintName]: off.}` as being a
pragma of kind `wHint` rather than an invalid pragma which would have to
be checked separately. From looking at the uses of `whichPragma` this
doesn't seem like it would cause problems.
Generics have [the same
problem](a27542195c/compiler/semgnrc.nim (L619))
(causing #18649), but to make it work we need to make sure the
templates/macros don't get evaluated or get evaluated correctly (i.e.
passing the proc node as the final argument), either with #23094 or by
completely disabling template/macro evaluation when processing the
pragma node, which would also cover `{.pragma.}` templates.
