Revert "deps: V8: cherry-pick 7107287"

This reverts commit 142b593.

PR-URL: #62894
Reviewed-By: René <contact.9a5d6388@renegade334.me.uk>
Reviewed-By: Abdirahim Musse <abdirahim.musse@ibm.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
(cherry picked from commit c028766)

Author: richardlau

common.gypi

@@ -38,7 +38,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.18',
+    'v8_embedder_string': '-node.17',
 
     ##### V8 defaults for Node.js #####
 

deps/v8/BUILD.gn

@@ -1627,7 +1627,7 @@ config("toolchain") {
   if (v8_current_cpu == "ppc64") {
     defines += [ "V8_TARGET_ARCH_PPC64" ]
     cflags += [ "-ffp-contract=off" ]
-    if (current_os == "aix" and !is_clang) {
+    if (current_os == "aix") {
       cflags += [
         # Work around AIX ceil, trunc and round oddities.
         "-mcpu=power5+",

deps/v8/src/builtins/ppc/builtins-ppc.cc

@@ -4201,19 +4201,6 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // If return value is on the stack, pop it to registers.
   if (needs_return_buffer) {
-    Label done;
-    if (switch_to_central_stack) {
-      Label no_stack_change;
-      __ CmpU64(kOldSPRegister, Operand(0), r0);
-      __ beq(&no_stack_change);
-      __ addi(r3, kOldSPRegister,
-              Operand((kStackFrameExtraParamSlot + 1) * kSystemPointerSize));
-      __ b(&done);
-      __ bind(&no_stack_change);
-    }
-    __ addi(r3, sp,
-            Operand((kStackFrameExtraParamSlot + 1) * kSystemPointerSize));
-    __ bind(&done);
     __ LoadU64(r4, MemOperand(r3, kSystemPointerSize));
     __ LoadU64(r3, MemOperand(r3));
   }

deps/v8/src/compiler/turboshaft/operations.h

@@ -525,7 +525,7 @@ class InputsRepFactory {
   };
 };
 
-struct __attribute__((packed))  EffectDimensions {
+struct EffectDimensions {
   // Produced by loads, consumed by operations that should not move before loads
   // because they change memory.
   bool load_heap_memory : 1;
@@ -620,7 +620,7 @@ static_assert(sizeof(EffectDimensions) == sizeof(EffectDimensions::Bits));
 // they become more restricted in their movement. Note that calls are not the
 // most side-effectful operations, as they do not leave the heap in an
 // inconsistent state, so they do not need to be marked as raw heap access.
-struct __attribute__((packed)) OpEffects {
+struct OpEffects {
   EffectDimensions produces;
   EffectDimensions consumes;
 
@@ -2904,7 +2904,7 @@ struct ConstantOp : FixedArityOperationT<0, ConstantOp> {
 // When result_rep is RegisterRepresentation::Compressed(), then the load does
 // not decompress the value.
 struct LoadOp : OperationT<LoadOp> {
-  struct __attribute__((packed)) Kind {
+  struct Kind {
     // The `base` input is a tagged pointer to a HeapObject.
     bool tagged_base : 1;
     // The effective address might be unaligned. This is only set to true if

deps/v8/src/execution/simulator.h

@@ -199,17 +199,13 @@ class GeneratedCode {
     return fn(args...);
 #else
     // AIX ABI requires function descriptors (FD).  Artificially create a pseudo
-    // FD to ensure correct dispatch to generated code.
-    void* function_desc[3];
-    Signature* fn;
-    asm("std %1, 0(%2)\n\t"
-        "li 0, 0\n\t"
-        "std 0, 8(%2)\n\t"
-        "std 0, 16(%2)\n\t"
-        "mr %0, %2\n\t"
-        : "=r"(fn)
-        : "r"(fn_ptr_), "r"(function_desc)
-        : "memory", "0");
+    // FD to ensure correct dispatch to generated code.  The 'volatile'
+    // declaration is required to avoid the compiler from not observing the
+    // alias of the pseudo FD to the function pointer, and hence, optimizing the
+    // pseudo FD declaration/initialization away.
+    volatile Address function_desc[] = {reinterpret_cast<Address>(fn_ptr_), 0,
+                                        0};
+    Signature* fn = reinterpret_cast<Signature*>(function_desc);
     return fn(args...);
 #endif  // V8_OS_ZOS
 #else

deps/v8/src/trap-handler/handler-shared.cc

@@ -24,11 +24,7 @@ namespace v8 {
 namespace internal {
 namespace trap_handler {
 
-#if defined(V8_OS_AIX)
-__thread bool TrapHandlerGuard::is_active_ = 0;
-#else
 thread_local bool TrapHandlerGuard::is_active_ = 0;
-#endif
 
 size_t gNumCodeObjects = 0;
 CodeProtectionInfoListEntry* gCodeObjects = nullptr;