Add DUK_USE_IDCHAR_FASTPATH option

config/config-options/DUK_USE_IDCHAR_FASTPATH.yaml

@@ -0,0 +1,10 @@
+define: DUK_USE_IDCHAR_FASTPATH
+introduced: 1.5.0
+default: true
+tags:
+  - performance
+  - fastpath
+  - lowmemory
+description: >
+  Enable fast path for identifier start/part tables, which affect lexing and
+  JSON performance slightly at a small cost in footprint.

config/examples/low_memory.yaml

@@ -28,6 +28,7 @@ DUK_USE_JSON_DECNUMBER_FASTPATH: false
 DUK_USE_JSON_EATWHITE_FASTPATH: false
 DUK_USE_BASE64_FASTPATH: false
 DUK_USE_HEX_FASTPATH: false
+DUK_USE_IDCHAR_FASTPATH: false
 DUK_USE_BYTECODE_DUMP_SUPPORT: false
 DUK_USE_JX: false
 DUK_USE_JC: false

config/examples/performance_sensitive.yaml

@@ -15,6 +15,7 @@ DUK_USE_JSON_DECNUMBER_FASTPATH: true
 DUK_USE_JSON_EATWHITE_FASTPATH: true
 DUK_USE_BASE64_FASTPATH: true
 DUK_USE_HEX_FASTPATH: true
+DUK_USE_IDCHAR_FASTPATH: true
 DUK_USE_INTERRUPT_COUNTER: false
 DUK_USE_DEBUGGER_SUPPORT: false
 DUK_USE_STRHASH_DENSE: false