[vm] Fix WriteByteSequence for simarm_x64

Bug: #36839
Change-Id: Ibf9ffda6be7a6585d90b4fb1430ae0b227609af6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/109482
Commit-Queue: Liam Appelbe <liama@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>

runtime/vm/image_snapshot.cc

@@ -811,8 +811,8 @@ void AssemblyImageWriter::FrameUnwindEpilogue() {
 }
 
 intptr_t AssemblyImageWriter::WriteByteSequence(uword start, uword end) {
-  for (uword* cursor = reinterpret_cast<uword*>(start);
-       cursor < reinterpret_cast<uword*>(end); cursor++) {
+  for (auto* cursor = reinterpret_cast<compiler::target::uword*>(start);
+       cursor < reinterpret_cast<compiler::target::uword*>(end); cursor++) {
     WriteWordLiteralText(*cursor);
   }
   return end - start;
@@ -841,11 +841,10 @@ BlobImageWriter::BlobImageWriter(Thread* thread,
 }
 
 intptr_t BlobImageWriter::WriteByteSequence(uword start, uword end) {
-  for (uword* cursor = reinterpret_cast<uword*>(start);
-       cursor < reinterpret_cast<uword*>(end); cursor++) {
-    instructions_blob_stream_.WriteWord(*cursor);
-  }
-  return end - start;
+  const uword size = end - start;
+  instructions_blob_stream_.WriteBytes(reinterpret_cast<const void*>(start),
+                                       size);
+  return size;
 }
 
 void BlobImageWriter::WriteText(WriteStream* clustered_stream, bool vm) {

runtime/vm/image_snapshot.h

@@ -10,6 +10,7 @@
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
+#include "vm/compiler/runtime_api.h"
 #include "vm/datastream.h"
 #include "vm/globals.h"
 #include "vm/growable_array.h"
@@ -313,7 +314,7 @@ class AssemblyImageWriter : public ImageWriter {
   void FrameUnwindPrologue();
   void FrameUnwindEpilogue();
   intptr_t WriteByteSequence(uword start, uword end);
-  void WriteWordLiteralText(uword value) {
+  void WriteWordLiteralText(compiler::target::uword value) {
 // Padding is helpful for comparing the .S with --disassemble.
 #if defined(TARGET_ARCH_IS_64_BIT)
     assembly_stream_.Print(".quad 0x%0.16" Px "\n", value);