Use general instruction/stack pointer convenience method instead of manually

src/processor/exploitability_win.cc

Index: src/processor/exploitability_win.cc
===================================================================
--- src/processor/exploitability_win.cc	(revision 1466)
+++ src/processor/exploitability_win.cc	(working copy)
@@ -106,20 +106,16 @@
   uint64_t stack_ptr = 0;
   uint64_t instruction_ptr = 0;
 
-  switch (context->GetContextCPU()) {
-    case MD_CONTEXT_X86:
-      stack_ptr = context->GetContextX86()->esp;
-      instruction_ptr = context->GetContextX86()->eip;
-      break;
-    case MD_CONTEXT_AMD64:
-      stack_ptr = context->GetContextAMD64()->rsp;
-      instruction_ptr = context->GetContextAMD64()->rip;
-      break;
-    default:
-      BPLOG(INFO) << "Unsupported architecture.";
-      return EXPLOITABILITY_ERR_PROCESSING;
+  // Getting the instruction pointer.
+  if (!context->GetInstructionPointer(&instruction_ptr)) {
+    return EXPLOITABILITY_ERR_PROCESSING;
   }
 
+  // Getting the stack pointer.
+  if (!context->GetStackPointer(&stack_ptr)) {
+    return EXPLOITABILITY_ERR_PROCESSING;
+  }
+
   // Check if we are executing on the stack.
   if (instruction_ptr <= (stack_ptr + kProbableStackOffset) &&
       instruction_ptr >= (stack_ptr - kProbableStackOffset))