Add extra test for nondet-static flag and arrays

This extra test is added to ensure that constant arrays,
which are known at compile time, do not produce a NONDET
instruction to initialise them at the GOTO level, after
we use goto-instrument with the --nondet-static flag.

Author: NlightNFotis

regression/goto-instrument/no_nondet_const/main.c

@@ -0,0 +1,8 @@
+int var;
+const int arr[] = {10, 20, 30};
+
+int main(void)
+{
+  var = arr[2];
+  return 0;
+}

regression/goto-instrument/no_nondet_const/test.desc

@@ -0,0 +1,8 @@
+CORE
+main.c
+--nondet-static
+^EXIT=0$
+^SIGNAL=0$
+--
+arr = NONDET\(const signed int \[3ll\]\)
+--