aix: fix function_descriptor issue on regexp

the problem is that we call irregexp code in two ways:

1. CallCFunction9 from CSA builtins
2. Through GeneratedCode::Call from the runtime.

1 is a standard C call and expects the target to be a FD,
2 is our own implementation where we dynamically generate a FD.
So there's a mismatch between the two.

Change-Id: I8391db30fa7586d296b5d1880a7f44dafad21a2a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1487341
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Auto-Submit: Junliang Yan <jyan@ca.ibm.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60129}

src/regexp/ppc/regexp-macro-assembler-ppc.cc

@@ -109,6 +109,9 @@ RegExpMacroAssemblerPPC::RegExpMacroAssemblerPPC(Isolate* isolate, Zone* zone,
       internal_failure_label_() {
   DCHECK_EQ(0, registers_to_save % 2);
 
+  // Because RegExp code respects C ABI, so needs a FD
+  __ function_descriptor();
+
   __ b(&entry_label_);  // We'll write the entry code later.
   // If the code gets too big or corrupted, an internal exception will be
   // raised, and we will exit right away.

src/regexp/regexp-macro-assembler.cc

@@ -273,8 +273,9 @@ int NativeRegExpMacroAssembler::Execute(
       int output_size, Address stack_base, int direct_call, Isolate* isolate);
 
   auto fn = GeneratedCode<RegexpMatcherSig>::FromCode(code);
-  int result = fn.Call(input.ptr(), start_offset, input_start, input_end,
-                       output, output_size, stack_base, direct_call, isolate);
+  int result =
+      fn.CallIrregexp(input.ptr(), start_offset, input_start, input_end, output,
+                      output_size, stack_base, direct_call, isolate);
   DCHECK(result >= RETRY);
 
   if (result == EXCEPTION && !isolate->has_pending_exception()) {

src/simulator.h

@@ -118,7 +118,10 @@ class GeneratedCode {
     return Simulator::current(isolate_)->template Call<Return>(
         reinterpret_cast<Address>(fn_ptr_), args...);
   }
+
+  DISABLE_CFI_ICALL Return CallIrregexp(Args... args) { return Call(args...); }
 #else
+
   DISABLE_CFI_ICALL Return Call(Args... args) {
     // When running without a simulator we call the entry directly.
 #if V8_OS_AIX
@@ -135,7 +138,12 @@ class GeneratedCode {
     return fn_ptr_(args...);
 #endif  // V8_OS_AIX
   }
-#endif
+
+  DISABLE_CFI_ICALL Return CallIrregexp(Args... args) {
+    // When running without a simulator we call the entry directly.
+    return fn_ptr_(args...);
+  }
+#endif  // USE_SIMULATOR
 
  private:
   friend class GeneratedCode<Return(Args...)>;