The following patch prevents build failures due to comparisons between
a pointer and an integer. It has been adapted from openjdk@10.

diff -u -r openjdk-9.alt/hotspot/src/share/vm/memory/virtualspace.cpp openjdk-9/hotspot/src/share/vm/memory/virtualspace.cpp
--- openjdk-9.alt/hotspot/src/share/vm/memory/virtualspace.cpp	2023-04-05 13:46:58.841965513 +0200
+++ openjdk-9/hotspot/src/share/vm/memory/virtualspace.cpp	2023-04-05 13:48:43.902387837 +0200
@@ -581,7 +581,7 @@
   assert(markOopDesc::encode_pointer_as_mark(&_base[size])->decode_pointer() == &_base[size],
          "area must be distinguishable from marks for mark-sweep");
 
-  if (base() > 0) {
+  if (base() != NULL) {
     MemTracker::record_virtual_memory_type((address)base(), mtJavaHeap);
   }
 }
diff -u -r openjdk-9.alt/hotspot/src/share/vm/opto/lcm.cpp openjdk-9/hotspot/src/share/vm/opto/lcm.cpp
--- openjdk-9.alt/hotspot/src/share/vm/opto/lcm.cpp	2023-04-05 13:46:58.849965545 +0200
+++ openjdk-9/hotspot/src/share/vm/opto/lcm.cpp	2023-04-05 13:47:53.566187260 +0200
@@ -39,7 +39,7 @@
 // Check whether val is not-null-decoded compressed oop,
 // i.e. will grab into the base of the heap if it represents NULL.
 static bool accesses_heap_base_zone(Node *val) {
-  if (Universe::narrow_oop_base() > 0) { // Implies UseCompressedOops.
+  if (Universe::narrow_oop_base() != NULL) { // Implies UseCompressedOops.
     if (val && val->is_Mach()) {
       if (val->as_Mach()->ideal_Opcode() == Op_DecodeN) {
         // This assumes all Decodes with TypePtr::NotNull are matched to nodes that