ipa-sra: Don't change return type to void if there are musttail calls [PR119484]

ipa-sra: Don't change return type to void if there are musttail calls [PR119484]

The following testcase is rejected, because IPA-SRA decides to
turn bar.constprop call into bar.constprop.isra which returns void.
While there is no explicit lhs on the call, as it is a musttail call
the tailc pass checks if IPA-VRP returns singleton from that function
and the function returns the same value and in that case it still turns
it into a tail call.  This can't work with IPA-SRA changing it into
void returning function though.

The following patch fixes this by forcing returning the original type
if there are musttail calls.

2025-03-28  Jakub Jelinek  <jakub@redhat.com>

	PR ipa/119484
	* ipa-sra.cc (isra_analyze_call): Don't set m_return_ignored if
	gimple_call_must_tail_p even if it doesn't have lhs.

	* c-c++-common/pr119484.c: New test.