string-replace-fewer-backslashes -> regex-easyesc

This shortens a very long feature name.

See discussion in #5805

share/functions/fish_clipboard_paste.fish

@@ -26,7 +26,7 @@ function fish_clipboard_paste
     #
     # This eases pasting non-code (e.g. markdown or git commitishes).
     if __fish_commandline_is_singlequoted
-        if status test-feature string-replace-fewer-backslashes
+        if status test-feature regex-easyesc
             set data (string replace -ra "(['\\\])" '\\\\$1' -- $data)
         else
             set data (string replace -ra "(['\\\])" '\\\\\\\$1' -- $data)

sphinx_doc_src/index.rst

@@ -1714,7 +1714,7 @@ You can see the current list of features via ``status features``::
     > status features
     stderr-nocaret  on     3.0      ^ no longer redirects stderr
     qmark-noglob    off    3.0      ? no longer globs
-    string-replace-fewer-backslashes        off     3.1     string replace -r needs fewer backslashes in the replacement
+    regex-easyesc   off    3.1      string replace -r needs fewer \\'s
 
 There are two breaking changes in fish 3.0: caret ``^`` no longer redirects stderr, and question mark ``?`` is no longer a glob.
 

src/future_feature_flags.cpp

@@ -13,8 +13,7 @@ features_t &mutable_fish_features() { return global_features; }
 const features_t::metadata_t features_t::metadata[features_t::flag_count] = {
     {stderr_nocaret, L"stderr-nocaret", L"3.0", L"^ no longer redirects stderr"},
     {qmark_noglob, L"qmark-noglob", L"3.0", L"? no longer globs"},
-    {string_replace_backslash, L"string-replace-fewer-backslashes", L"3.1",
-     L"string replace -r needs fewer backslashes in the replacement"},
+    {string_replace_backslash, L"regex-easyesc", L"3.1", L"string replace -r needs fewer \\'s"},
 };
 
 const struct features_t::metadata_t *features_t::metadata_for(const wchar_t *name) {