patch 8.1.0020: cannot tell whether a register is executing or recording

Problem:    Cannot tell whether a register is being used for executing or
            recording.
Solution:   Add reg_executing() and reg_recording(). (Hirohito Higashi,
            closes #2745)  Rename the global variables for consistency.  Store
            the register name in reg_executing.
diff --git a/src/globals.h b/src/globals.h
index d5320d7..22199c9 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -933,8 +933,8 @@
 EXTERN int exmode_active INIT(= 0);	/* zero, EXMODE_NORMAL or EXMODE_VIM */
 EXTERN int ex_no_reprint INIT(= FALSE); /* no need to print after z or p */
 
-EXTERN int Recording INIT(= FALSE);	/* TRUE when recording into a reg. */
-EXTERN int Exec_reg INIT(= FALSE);	/* TRUE when executing a register */
+EXTERN int reg_recording INIT(= 0);	/* register for recording  or zero */
+EXTERN int reg_executing INIT(= 0);	/* register being executed or zero */
 
 EXTERN int no_mapping INIT(= FALSE);	/* currently no mapping allowed */
 EXTERN int no_zero_mapping INIT(= 0);	/* mapping zero not allowed */