match: Fix `!a?b:c` and `a?~t:t` patterns for signed 1 bit types [PR114666]

The problem is `!a?b:c` pattern will create a COND_EXPR with an 1bit signed integer
which breaks patterns like `a?~t:t`. This rejects when we have a signed operand for
both patterns.

Note for GCC 15, I am going to look at the canonicalization of `a?~t:t` where t
was a constant since I think keeping it a COND_EXPR might be more canonical and
is what VPR produces from the same IR; if anything expand should handle which one
is better.

Bootstrapped and tested on x86_64-linux-gnu with no regressions.

	PR tree-optimization/114666

gcc/ChangeLog:

	* match.pd (`!a?b:c`): Reject signed types for the condition.
	(`a?~t:t`): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.c-torture/execute/bitfld-signed1-1.c: New test.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.c-torture/execute/bitfld-signed1-1.c b/gcc/testsuite/gcc.c-torture/execute/bitfld-signed1-1.c
new file mode 100644
index 0000000..b0ff120
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/bitfld-signed1-1.c
@@ -0,0 +1,13 @@
+/* PR tree-optimization/114666 */
+/* We used to miscompile this to be always aborting
+   due to the use of the signed 1bit into the COND_EXPR. */
+
+struct {
+  signed a : 1;
+} b = {-1};
+char c;
+int main()
+{
+  if ((b.a ^ 1UL) < 3)
+    __builtin_abort();
+}