[cli/loader]: Don't allow initialization to run more than once

There are multiple ways of fixing this, but let's just not let
trampolines get re-set after they've already been set.

Author: staticfloat

cli/loader_lib.c

@@ -130,6 +130,11 @@ JL_DLLEXPORT const char * jl_get_libdir()
 
 void * libjulia_internal = NULL;
 __attribute__((constructor)) void jl_load_libjulia_internal(void) {
+    // Only initalize this once
+    if (libjulia_internal != NULL) {
+        return;
+    }
+
     // Introspect to find our own path
     const char * lib_dir = jl_get_libdir();