[pushed] c++: Fix consteval operator handling.

[Jason Merrill via Gcc-patches]

We were crashing trying to find the CALL_EXPR in the result of a call to a
consteval operator.

Tested x86_64-pc-linux-gnu, applying to trunk.

gcc/cp/ChangeLog:

        * call.c (build_new_op_1): Don't look for a CALL_EXPR when
        calling a consteval function.

gcc/testsuite/ChangeLog:

        * g++.dg/cpp2a/consteval17.C: New test.
---
 gcc/cp/call.c                            |  2 +-
 gcc/testsuite/g++.dg/cpp2a/consteval17.C | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/consteval17.C

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 1d95bd2d07b..5382b7620dc 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -6341,7 +6341,7 @@ build_new_op_1 (const op_location_t &loc, enum tree_code 
code, int flags,
              result = build_over_call (cand, LOOKUP_NORMAL, ocomplain);
            }
 
-         if (trivial_fn_p (cand->fn))
+         if (trivial_fn_p (cand->fn) || DECL_IMMEDIATE_FUNCTION_P (cand->fn))
            /* There won't be a CALL_EXPR.  */;
          else if (result && result != error_mark_node)
            {
diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval17.C 
b/gcc/testsuite/g++.dg/cpp2a/consteval17.C
new file mode 100644
index 00000000000..6af39aad8da
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/consteval17.C
@@ -0,0 +1,11 @@
+// { dg-do compile { target c++20 } }
+
+struct A
+{
+  consteval int operator+() { return 42; }
+};
+
+int main()
+{
+  +A();
+}

base-commit: da2c9054f1596b71e3c81efd62b6cef348e445b4
-- 
2.18.1