Fix PR c++/111106: missing ; causes internal compiler error

We currently fail upon the following because an assert in dependent_type_p
fails for f's parameter

=== cut here ===
consteval int id (int i) { return i; }
constexpr int
f (auto i) requires requires { id (i) } { return i; }
void g () { f (42); }
=== cut here ===

This patch fixes this by relaxing the assert to pass during error recovery.

Successfully tested on x86_64-pc-linux-gnu.

	PR c++/111106

gcc/cp/ChangeLog:

	* pt.cc (dependent_type_p): Don't fail assert during error recovery.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/consteval37.C: New test.

2 files changed, 18 insertions, 1 deletions

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index dfce1b3..edb94a0 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -28019,7 +28019,8 @@ dependent_type_p (tree type)
       /* If we are not processing a template, then nobody should be
 	 providing us with a dependent type.  */
       gcc_assert (type);
-      gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
+      gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type)
+		  || seen_error());
       return false;
     }
 
diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval37.C b/gcc/testsuite/g++.dg/cpp2a/consteval37.C
new file mode 100644
index 0000000..519d83d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/consteval37.C
@@ -0,0 +1,16 @@
+// PR c++/111106
+// { dg-do compile { target c++20 } }
+
+consteval int id (int i) { return i; }
+
+constexpr int f (auto i)
+  requires requires { id (i) } // { dg-error "expected" }
+{
+  return i;
+}
+
+void g () {
+  f (42);
+}
+
+// { dg-excess-errors "" }