Add evil-want-treat-composed-chars-as-one option

Allows user to disable special handling of composed characters. See the
docstring for more information.

evil-common.el

@@ -3000,13 +3000,14 @@ the positions to be outside of this sequence."
     (when (and (numberp beg) (numberp end))
       (setq beg-out (min beg end))
       (setq end-out (max beg end))
-      (let ((comp (find-composition beg-out)))
-        ;; find-composition returns (FROM TO VALID-P)
-        (when (and (listp comp) (nth 2 comp))
-          (setq beg-out (nth 0 comp))))
-      (let ((comp (find-composition end-out)))
-        (when (and (listp comp) (nth 2 comp))
-          (setq end-out (nth 1 comp))))
+      (when evil-want-treat-composed-chars-as-one
+        (let ((comp (find-composition beg-out)))
+          ;; find-composition returns (FROM TO VALID-P)
+          (when (and (listp comp) (nth 2 comp))
+            (setq beg-out (nth 0 comp))))
+        (let ((comp (find-composition end-out)))
+          (when (and (listp comp) (nth 2 comp))
+            (setq end-out (nth 1 comp)))))
       (append (list beg-out end-out)
               (when (evil-type-p type)
                 (list type))

evil-vars.el

@@ -1104,6 +1104,19 @@ without having to introduce new niche functionality.
 Prefer to set `evil-v$-excludes-newline' to non-nil."
  "1.15.0")
 
+(defcustom evil-want-treat-composed-chars-as-one nil
+  "EXPERIMENTAL. Treat composed characters as single characters.
+
+Composed characters are sequences of characters in the buffer
+that are displayed as a single glyph. This is the device used by
+`prettify-symbols-mode' among others. This option tells evil that
+these sequences of characters should be treated as a single unit
+to, for example, prevent part of the sequence from being deleted
+by an evil command. It alters low-level functionality of evil and
+is considered experimental."
+  :type 'boolean
+  :group 'evil)
+
 (defcustom evil-v$-excludes-newline nil
   "If non-nil, `evil-end-of-line' does not move as far as to include
 the `\n' char at eol. This makes `v$' consistent with `$' used as a