IDL: Drop value conversion (V8 -> C++) macros from generated code

Source/bindings/templates/conversions.cpp

Index: Source/bindings/templates/conversions.cpp
diff --git a/Source/bindings/templates/conversions.cpp b/Source/bindings/templates/conversions.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5196c6af64e50e7a7412e4b79e261562a7893170
--- /dev/null
+++ b/Source/bindings/templates/conversions.cpp
@@ -0,0 +1,37 @@
+{% macro v8_value_to_local_cpp_value(thing) %}
+{# This indirection is just to avoid spurious white-space lines. #}
+{{generate_v8_value_to_local_cpp_value(thing) | trim}}
+{%- endmacro %}
+
+
+{% macro generate_v8_value_to_local_cpp_value(thing) %}
+{% set item = thing.v8_value_to_local_cpp_value or thing %}
+{% if item.error_message %}
+/* {{item.error_message}} */
+{% else %}
+{% if item.declare_variable %}
+{% if item.assign_expression %}
+{{item.cpp_type}} {{item.cpp_name}} = {{item.assign_expression}};
+{% else %}
+{{item.cpp_type}} {{item.cpp_name}};
+{% endif %}
+{% else %}{# item.declare_variable #}
+{% if item.assign_expression %}
+{{item.cpp_name}} = {{item.assign_expression}};
+{% endif %}
+{% endif %}{# item.declare_variable #}
+{% if item.check_expression %}
+{% if item.throw_expression %}
+if ({{item.check_expression}}) {
+    {{item.throw_expression}};
+    return{% if item.return_expression %} {{item.return_expression}}{% endif %};
+}
+{% else %}
+if ({{item.check_expression}})
+    return{% if item.return_expression %} {{item.return_expression}}{% endif %};
+{% endif %}
+{% endif %}{# item.check_expression #}
+{% endif %}{# item.error_message #}
+{% endmacro %}
+
+