The generated code by yarpgen failed. I traced the problem to
expr_landor. The problem was that nocode_wanted was removing
too much code.
See also testcase 33.
the code in expr_cond save nocode_wanted around some parts of
expression evaluation, but at the wrong spots. If the evaluation
of the condition itself (e.g. in the testcase the first whole ternary
expression) resulted in CODE_OFF, then that was saved, and restored
before return, even if in-between codegen would have CODE_ON'ed already.
Thus the whole CODE_OFF state bled out to outside the expression
evaluation and also disabled the whole if-block. Found by yarpgen v1
(seed 64).
as there's overlap between handling types for binary and ternay
operations. Factor this into a single routine (combine_types).
This uses the structure that gen_op was following, and expr_cond
was using as well in the past, which I find easier to reconvene
with the standard language. But it reuses the new functions for
diagnostics to improve (a little) on what GCC or clang produce :)
