makeRecipes() reset the current target on every non-tab line, so an
ifeq/endif block ended the recipe and every tab-indented line inside it
was discarded; and the target line's tail was read entirely as
prerequisites, so `check: ; @script/fmt-check` split to tokens that
named no target and vanished. Both gave `make check` a second prettier
pass with the suite green.
Conditional directives no longer end a recipe, and every branch is
treated as reachable rather than evaluating the condition. The target
line is split on the first `;`: what precedes it is the prerequisite
list, what follows is the first recipe line. Both pinned directly, and
the header's exclusion list now names what the parser actually skips.
Reflow the heredoc RUN fixture array in the BuildKit heredoc test to
satisfy prettier --check, which rejected the single-line form. No
behavioural change to the tests or the resolver.