Debug info: emit real types for global variables

When emitting debug info for global variables, emit real types instead
of types that are internally used in codegen. This mainly applies to:
- pointers which are internally represented as integers
- structs which are internally represented as byte arrays

Similarly to kernel functions, we will need to emit debug info for
global variables that matches their BTF in the kernel so we need the
actual types.

Author: viktormalik

src/ast/dibuilderbpf.cpp

@@ -347,7 +347,7 @@ DIGlobalVariableExpression *DIBuilderBPF::createGlobalVariable(
     const SizedType &stype)
 {
   return createGlobalVariableExpression(
-      file, name, "global", file, 0, GetType(stype), false);
+      file, name, "global", file, 0, GetType(stype, false), false);
 }
 
 } // namespace bpftrace::ast