[compiler] Delay allocation of code-embedded heap numbers.

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
diff --git a/src/x64/assembler-x64.cc b/src/x64/assembler-x64.cc
index b2330b3320b36cafbc2af670e853ea52d6489094..283caf2c832703c5f84a86299edce4f1b715d2a9 100644
--- a/src/x64/assembler-x64.cc
+++ b/src/x64/assembler-x64.cc
@@ -309,11 +309,13 @@ Assembler::Assembler(IsolateData isolate_data, void* buffer, int buffer_size)
   reloc_info_writer.Reposition(buffer_ + buffer_size_, pc_);
 }
 
-
-void Assembler::GetCode(CodeDesc* desc) {
-  // Finalize code (at this point overflow() may be true, but the gap ensures
-  // that we are still not overlapping instructions and relocation info).
+void Assembler::GetCode(Isolate* isolate, CodeDesc* desc) {
+  // At this point overflow() may be true, but the gap ensures
+  // that we are still not overlapping instructions and relocation info.
   DCHECK(pc_ <= reloc_info_writer.pos());  // No overlap.
+
+  AllocateRequestedHeapNumbers(isolate);
+
   // Set up code descriptor.
   desc->buffer = buffer_;
   desc->buffer_size = buffer_size_;
@@ -1538,6 +1540,14 @@ void Assembler::movp(Register dst, void* value, RelocInfo::Mode rmode) {
   emitp(value, rmode);
 }
 
+void Assembler::movp_heap_number(Register dst, double value) {
+  EnsureSpace ensure_space(this);
+  emit_rex(dst, kPointerSize);
+  emit(0xB8 | dst.low_bits());
+  RequestHeapNumber(value);
+  emitp(nullptr, RelocInfo::EMBEDDED_OBJECT);
+}
+
 void Assembler::movq(Register dst, int64_t value, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
   emit_rex_64(dst);