[Interpreter] Make InterpreterAssembler a subclass of CodeStubAssembler.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index ae58e53473d720393cd6feacc05faa5c3759944d..c9bd4e107d7eafe7930534895a88925c45d3716e 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -785,8 +785,6 @@ source_set("v8_base") {
     "src/compiler/instruction.h",
     "src/compiler/int64-lowering.cc",
     "src/compiler/int64-lowering.h",
-    "src/compiler/interpreter-assembler.cc",
-    "src/compiler/interpreter-assembler.h",
     "src/compiler/js-builtin-reducer.cc",
     "src/compiler/js-builtin-reducer.h",
     "src/compiler/js-call-reducer.cc",
@@ -1123,6 +1121,8 @@ source_set("v8_base") {
     "src/interpreter/handler-table-builder.h",
     "src/interpreter/interpreter.cc",
     "src/interpreter/interpreter.h",
+    "src/interpreter/interpreter-assembler.cc",
+    "src/interpreter/interpreter-assembler.h",
     "src/interpreter/register-translator.cc",
     "src/interpreter/register-translator.h",
     "src/interpreter/source-position-table.cc",