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/evalfunc.c b/src/evalfunc.c
index 46e55b3..90aa2ef 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -306,6 +306,8 @@
 #endif
 static void f_range(typval_T *argvars, typval_T *rettv);
 static void f_readfile(typval_T *argvars, typval_T *rettv);
+static void f_reg_executing(typval_T *argvars, typval_T *rettv);
+static void f_reg_recording(typval_T *argvars, typval_T *rettv);
 static void f_reltime(typval_T *argvars, typval_T *rettv);
 #ifdef FEAT_FLOAT
 static void f_reltimefloat(typval_T *argvars, typval_T *rettv);
@@ -754,6 +756,8 @@
 #endif
     {"range",		1, 3, f_range},
     {"readfile",	1, 3, f_readfile},
+    {"reg_executing",	0, 0, f_reg_executing},
+    {"reg_recording",	0, 0, f_reg_recording},
     {"reltime",		0, 2, f_reltime},
 #ifdef FEAT_FLOAT
     {"reltimefloat",	1, 1, f_reltimefloat},
@@ -8697,6 +8701,34 @@
     fclose(fd);
 }
 
+    static void
+return_register(int regname, typval_T *rettv)
+{
+    char_u buf[2] = {0, 0};
+
+    buf[0] = (char_u)regname;
+    rettv->v_type = VAR_STRING;
+    rettv->vval.v_string = vim_strsave(buf);
+}
+
+/*
+ * "reg_executing()" function
+ */
+    static void
+f_reg_executing(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    return_register(reg_executing, rettv);
+}
+
+/*
+ * "reg_recording()" function
+ */
+    static void
+f_reg_recording(typval_T *argvars UNUSED, typval_T *rettv)
+{
+    return_register(reg_recording, rettv);
+}
+
 #if defined(FEAT_RELTIME)
 static int list2proftime(typval_T *arg, proftime_T *tm);