[test] Add negative test for crash related to ClangTypeConverter.

Author: varungandhi-apple

test/ClangImporter/blocks_returning_bool.swift

@@ -1,5 +1,9 @@
 // RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -emit-silgen %s -I %S/Inputs/ | %FileCheck %s
 
+// Check that bridging an @convention(c)'s function's @convention(block)
+// parameter to a Swift function type doesn't crash the compiler.
+// RUN: not --crash %target-swift-frontend(mock-sdk: %clang-importer-sdk) -emit-silgen %s -I %S/Inputs/ -o /dev/null -use-clang-function-types -experimental-print-full-convention
+
 // REQUIRES: objc_interop
 
 import Foundation