Upgrade rust/crates/regex to 1.5.4

Test: make
Change-Id: I0eab39246dc2aea41a62c15661e350b490f06c1d
diff --git a/src/re_set.rs b/src/re_set.rs
index 5cb47ad..73d5953 100644
--- a/src/re_set.rs
+++ b/src/re_set.rs
@@ -7,10 +7,10 @@
             use std::slice;
             use std::vec;
 
-            use error::Error;
-            use exec::Exec;
-            use re_builder::$builder_mod::RegexSetBuilder;
-            use re_trait::RegularExpression;
+            use crate::error::Error;
+            use crate::exec::Exec;
+            use crate::re_builder::$builder_mod::RegexSetBuilder;
+            use crate::re_trait::RegularExpression;
 
 /// Match multiple (possibly overlapping) regular expressions in a single scan.
 ///
@@ -292,7 +292,7 @@
     /// This will always produces matches in ascending order of index, where
     /// the index corresponds to the index of the regex that matched with
     /// respect to its position when initially building the set.
-    pub fn iter(&self) -> SetMatchesIter {
+    pub fn iter(&self) -> SetMatchesIter<'_> {
         SetMatchesIter((&*self.matches).into_iter().enumerate())
     }
 }
@@ -405,7 +405,7 @@
 }
 
 impl fmt::Debug for RegexSet {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "RegexSet({:?})", self.0.regex_strings())
     }
 }