Use ICU case conversion/transliterator for case conversion behind a flag

src/v8.gyp

Index: src/v8.gyp
diff --git a/src/v8.gyp b/src/v8.gyp
index 402ca72b2dba89cd6bf907c7baf3483291f6a98d..f3e2bb5a2b20803fc46981f511f9c0b52b4e0613 100644
--- a/src/v8.gyp
+++ b/src/v8.gyp
@@ -1987,17 +1987,6 @@
         }, {
           'toolsets': ['target'],
         }],
-        ['v8_enable_i18n_support==1', {
-          'variables': {
-            'i18n_library_files': [
-              'js/i18n.js',
-            ],
-          },
-        }, {
-          'variables': {
-            'i18n_library_files': [],
-          },
-        }],
       ],
       'variables': {
         'library_files': [
@@ -2047,6 +2036,12 @@
         'libraries_experimental_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-experimental.bin',
         'libraries_extras_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-extras.bin',
         'libraries_experimental_extras_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-experimental-extras.bin',
+        'conditions': [
+          ['v8_enable_i18n_support==1', {
+            'library_files': ['js/i18n.js'],
+            'experimental_library_files': ['js/icu-case-mapping.js'],
+          }],
+        ],
       },
       'actions': [
         {
@@ -2054,7 +2049,6 @@
           'inputs': [
             '../tools/js2c.py',
             '<@(library_files)',
-            '<@(i18n_library_files)'
           ],
           'outputs': ['<(SHARED_INTERMEDIATE_DIR)/libraries.cc'],
           'action': [
@@ -2063,7 +2057,6 @@
             '<(SHARED_INTERMEDIATE_DIR)/libraries.cc',
             'CORE',
             '<@(library_files)',
-            '<@(i18n_library_files)'
           ],
         },
         {
@@ -2071,7 +2064,6 @@
           'inputs': [
             '../tools/js2c.py',
             '<@(library_files)',
-            '<@(i18n_library_files)'
           ],
           'outputs': ['<@(libraries_bin_file)'],
           'action': [
@@ -2080,7 +2072,6 @@
             '<(SHARED_INTERMEDIATE_DIR)/libraries.cc',
             'CORE',
             '<@(library_files)',
-            '<@(i18n_library_files)',
             '--startup_blob', '<@(libraries_bin_file)',
             '--nojs',
           ],
@@ -2097,7 +2088,7 @@
             '../tools/js2c.py',
             '<(SHARED_INTERMEDIATE_DIR)/experimental-libraries.cc',
             'EXPERIMENTAL',
-            '<@(experimental_library_files)'
+            '<@(experimental_library_files)',
           ],
         },
         {