build(rust): vendor googletest crate

third_party/crates/regex-automata-0.4.18/src/util/unicode_data/mod.rs

@@ -0,0 +1,17 @@
+// This cfg should match the one in src/util/look.rs that uses perl_word.
+#[cfg(all(
+    // We have to explicitly want to support Unicode word boundaries.
+    feature = "unicode-word-boundary",
+    not(all(
+        // If we don't have regex-syntax at all, then we definitely need to
+        // bring our own \w data table.
+        feature = "syntax",
+        // If unicode-perl is enabled, then regex-syntax/unicode-perl is
+        // also enabled, which in turn means we can use regex-syntax's
+        // is_word_character routine (and thus use its data tables). But if
+        // unicode-perl is not enabled, even if syntax is, then we need to
+        // bring our own.
+        feature = "unicode-perl",
+    )),
+))]
+pub(crate) mod perl_word;