revert: undo review changes to pre-existing code

- dwarf.h: restore u32 cfa (was already u32 on main; int was wrong)
- vmStructs.cpp: remove isThreadAccessible() guard from getExecutionMode/getOSThreadState (pre-existing code, not part of this branch)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: jbachorik

ddprof-lib/src/main/cpp/dwarf.h

@@ -74,7 +74,7 @@ const int INITIAL_PC_OFFSET = DW_LINK_REGISTER;
 
 struct FrameDesc {
     u32 loc;
-    int cfa;
+    u32 cfa;
     int fp_off;
     int pc_off;
 

ddprof-lib/src/main/cpp/hotspot/vmStructs.cpp

@@ -696,7 +696,7 @@ ExecutionMode VMThread::getExecutionMode() {
 
   VMThread* vm_thread = VMThread::current();
   // Not a JVM thread - native thread, e.g. thread launched by JNI code
-  if (vm_thread == nullptr || !vm_thread->isThreadAccessible()) {
+  if (vm_thread == nullptr) {
     return ExecutionMode::NATIVE;
   }
 
@@ -722,7 +722,7 @@ ExecutionMode VMThread::getExecutionMode() {
 
 OSThreadState VMThread::getOSThreadState() {
   VMThread* vm_thread = VMThread::current();
-  if (vm_thread == nullptr || !vm_thread->isThreadAccessible()) {
+  if (vm_thread == nullptr) {
     return OSThreadState::UNKNOWN;
   }
   int raw_thread_state = vm_thread->state();