Two RUN lines produce outputs that, each, have some common parts and
some different parts. The common parts are checked under label A. The
differing parts are associated to a function and checked under labels B
and C, respectivelly.
When build_function_body_dictionary is called for the first RUN line, it
will attribute the function body to labels A and C. When the second RUN
is passed to build_function_body_dictionary, it sees that the function
body under A is different from what it has. If in this second RUN line,
A were at the end of the prefixes list, A's body is still kept
associated with the first run's function.
When we output the function body (i.e. add_checks), we stop after
emitting for the first prefix matching that function. So we end up with
the wrong function body (first RUN's A-association).
There is no reason to special-case the last label in the prefixes list,
and the fix is to always clear a label association if we find a RUN line
where the body is different.
Differential Revision: https://reviews.llvm.org/D93078
Mircea Trofin