build: add v8_enable_temporal_systemicu

- switch needed to enable Temporal with system-icu
- also update configure.py to no longer disable Temporal

Signed-off-by: Steven R. Loomis <srl295@gmail.com>
PR-URL: #65992
Fixes: #62676
Refs: srl295/v8@cd89fe6
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Richard Lau <richard.lau@ibm.com>

Author: srl295

configure.py

@@ -2261,9 +2261,6 @@ def configure_v8(o, configs):
       case 'none':
         warn('Temporal support disabled when compiling without ICU')
         options.v8_disable_temporal_support = True
-      case 'system-icu':
-        warn('Temporal support disabled when compiling with a shared ICU library')
-        options.v8_disable_temporal_support = True
   o['variables']['v8_enable_temporal_support'] = 0 if options.v8_disable_temporal_support else 1
   o['variables']['v8_trace_maps'] = 1 if options.trace_maps else 0
   o['variables']['v8_use_perfetto'] = 1 if options.with_perfetto else 0
@@ -2544,6 +2541,8 @@ def icu_download(path):
   # always set icu_small, node.gyp depends on it being defined.
   o['variables']['icu_small'] = b(False)
   o['variables']['icu_system'] = b(False)
+  # always set this
+  o['variables']['v8_enable_temporal_systemicu'] = 1
 
   # prevent data override
   o['defines'] += ['ICU_NO_USER_DATA_OVERRIDE']

tools/v8_gypfiles/features.gypi

@@ -303,6 +303,11 @@
     # Enable Temporal API. Enabling this feature will
     # add a dependency on the temporal_rs library.
     'v8_enable_temporal_support%': 0,
+    # Enable Temporal even with system-icu.
+    # This will use an improved codepath which does not
+    # depend on internal ICU headers.
+    # This option can be on unconditionally.
+    'v8_enable_temporal_systemicu%': 1,
 
     # Lite mode disables a number of performance optimizations to reduce memory
     # at the cost of performance.
@@ -425,6 +430,9 @@
       }],
       ['v8_enable_temporal_support==1', {
         'defines': ['V8_TEMPORAL_SUPPORT',],
+      }],
+       ['v8_enable_temporal_systemicu==1', {
+        'defines': ['V8_ENABLE_TEMPORAL_SYSTEMICU',],
       }],
       # Refs: https://github.com/nodejs/node/pull/23801
       # ['v8_enable_handle_zapping==1', {