patch 8.2.3914: various spelling mistakes in comments

Problem:    Various spelling mistakes in comments.
Solution:   Fix the mistakes. (Dominique Pellé, closes #9416)
diff --git a/src/edit.c b/src/edit.c
index 9ff1c18..f4e9327 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -1657,8 +1657,8 @@
  */
 static int  pc_status;
 #define PC_STATUS_UNSET	0	// pc_bytes was not set
-#define PC_STATUS_RIGHT	1	// right halve of double-wide char
-#define PC_STATUS_LEFT	2	// left halve of double-wide char
+#define PC_STATUS_RIGHT	1	// right half of double-wide char
+#define PC_STATUS_LEFT	2	// left half of double-wide char
 #define PC_STATUS_SET	3	// pc_bytes was filled
 static char_u pc_bytes[MB_MAXBYTES + 1]; // saved bytes
 static int  pc_attr;