Add crashing test

Author: gamesh411

clang/test/Analysis/block-in-critical-section.c

@@ -0,0 +1,6 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.unix.BlockInCriticalSection -verify %s
+// expected-no-diagnostics
+
+// This should not crash
+int (*a)(void);
+void b(void) { a(); }