fix tests hang with clang as reported in https://bugs.gentoo.org/924958

patch from upstream PR at https://github.com/cpputest/cpputest/pull/1679
commit https://github.com/cpputest/cpputest/commit/094df52c8f6dae1dccb30d0d39dd1eb832ded85c
adapt to v4.0

diff --git a/src/CppUTest/Utest.cpp b/src/CppUTest/Utest.cpp
index d078bdf..3cbbcdf 100644
--- a/src/CppUTest/Utest.cpp
+++ b/src/CppUTest/Utest.cpp
@@ -153,7 +153,7 @@ UtestShell::~UtestShell()
 // LCOV_EXCL_START - actually covered but not in .gcno due to race condition
 static void defaultCrashMethod()
 {
-    UtestShell* ptr = (UtestShell*) NULLPTR; ptr->countTests();
+    abort();
 }
 // LCOV_EXCL_STOP
 
diff --git a/tests/CppUTest/UtestTest.cpp b/tests/CppUTest/UtestTest.cpp
index cf6ad1c..a26fb41 100644
--- a/tests/CppUTest/UtestTest.cpp
+++ b/tests/CppUTest/UtestTest.cpp
@@ -222,8 +222,7 @@ TEST(UtestShell, TestDefaultCrashMethodInSeparateProcessTest)
     fixture.runAllTests();
     fixture.assertPrintContains("Failed in separate process - killed by signal");
 
-    /* Signal 11 usually happens, but with clang3.7 on Linux, it produced signal 4 */
-    CHECK(fixture.getOutput().contains("signal 11") || fixture.getOutput().contains("signal 4"));
+    CHECK(fixture.getOutput().contains("signal 6"));
 }
 
 #endif