Add attribute [[noreturn]] (C++11) to functions that will not return

Rationale:
* Reduce the number of false positives from static analyzers
* Potentially enable additional compiler optimizations

src/random.cpp

@@ -39,10 +39,10 @@
 #include <openssl/err.h>
 #include <openssl/rand.h>
 
-static void RandFailure()
+[[noreturn]] static void RandFailure()
 {
     LogPrintf("Failed to read randomness, aborting\n");
-    abort();
+    std::abort();
 }
 
 static inline int64_t GetPerformanceCounter()