Add ES7-ES9 blanket config options

config/config-options/DUK_USE_ES7.yaml

@@ -0,0 +1,7 @@
+define: DUK_USE_ES7
+introduced: 2.0.0
+default: true
+tags:
+  - ecmascript2016
+description: >
+  Enable ES7 functionality not covered by other specific config options.

config/config-options/DUK_USE_ES8.yaml

@@ -0,0 +1,7 @@
+define: DUK_USE_ES8
+introduced: 2.0.0
+default: true
+tags:
+  - ecmascript2017
+description: >
+  Enable ES8 functionality not covered by other specific config options.

config/config-options/DUK_USE_ES9.yaml

@@ -0,0 +1,7 @@
+define: DUK_USE_ES9
+introduced: 2.0.0
+default: true
+tags:
+  - ecmascript2018
+description: >
+  Enable ES9 functionality not covered by other specific config options.

config/examples/low_memory.yaml

@@ -116,6 +116,10 @@ DUK_USE_FUNC_NAME_PROPERTY: true  # compliance
 DUK_USE_FUNC_FILENAME_PROPERTY: false  # non-standard, can be removed
 
 # Consider these; disabled by default because they don't impact E5 compliance.
+DUK_USE_ES6: false
+DUK_USE_ES7: false
+DUK_USE_ES8: false
+DUK_USE_ES9: false
 DUK_USE_COROUTINE_SUPPORT: false
 DUK_USE_SOURCE_NONBMP: false  # <300 bytes footprint
 DUK_USE_ES6_PROXY: false  # roughly 2kB footprint
@@ -125,5 +129,4 @@ DUK_USE_ES6_UNICODE_ESCAPE: false
 DUK_USE_HTML_COMMENTS: false
 DUK_USE_SHEBANG_COMMENTS: false
 DUK_USE_REFLECT_BUILTIN: false
-DUK_USE_ES6: false
 DUK_USE_SYMBOL_BUILTIN: false

config/tags.yaml

@@ -15,6 +15,9 @@ ecmascript2016:
 ecmascript2017:
   title: Ecmascript 2017 (ES8) options
 
+ecmascript2018:
+  title: Ecmascript 2018 (ES9) options
+
 duktape:
   title: Duktape specific options