LibSymbolication+SystemMonitor+bt: Move symbolication back in-process

Process-separated symbolication was cute, but ultimately the threat
model is kinda silly. We're already *running* the binary, but we're
afraid to parse its symbol table? :^)

This commit makes SystemMonitor and bt do symbolication in-process.
SymbolServer and the symbol user will be removed separately.

Userland/Applications/SystemMonitor/main.cpp

@@ -140,6 +140,11 @@ int main(int argc, char** argv)
         return 1;
     }
 
+    if (unveil("/usr/lib", "r") < 0) {
+        perror("unveil");
+        return 1;
+    }
+
     if (unveil("/bin/Profiler", "rx") < 0) {
         perror("unveil");
         return 1;