Split ignoreException to avoid suppressing CTRL-C

This splits `ignoreException` into `ignoreExceptionExceptInterrupt`
(which ignores all exceptions except `Interrupt`, which indicates a
SIGINT/CTRL-C) and `ignoreExceptionInDestructor` (which ignores all
exceptions, so that destructors do not throw exceptions).

This prevents many cases where Nix ignores CTRL-C entirely.
See: https://github.com/NixOS/nix/issues/7245

Upstream-PR: https://github.com/NixOS/nix/pull/11618
Change-Id: Ie7d2467eedbe840d1b9fa2e88a4e88e4ab26a87b

src/libexpr/eval-cache.cc

@@ -79,7 +79,7 @@ struct AttrDb
                 state->txn->commit();
             state->txn.reset();
         } catch (...) {
-            ignoreException();
+            ignoreExceptionInDestructor();
         }
     }
 
@@ -90,7 +90,7 @@ struct AttrDb
         try {
             return fun();
         } catch (SQLiteError &) {
-            ignoreException();
+            ignoreExceptionExceptInterrupt();
             failed = true;
             return 0;
         }
@@ -329,7 +329,7 @@ static std::shared_ptr<AttrDb> makeAttrDb(
     try {
         return std::make_shared<AttrDb>(cfg, fingerprint, symbols);
     } catch (SQLiteError &) {
-        ignoreException();
+        ignoreExceptionExceptInterrupt();
         return nullptr;
     }
 }