patch 9.1.0831: 'findexpr' can't be used as lambad or Funcref

Problem:  'findexpr' can't be used for lambads
          (Justin Keyes)
Solution: Replace the findexpr option with the findfunc option
          (Yegappan Lakshmanan)

related: #15905
closes: #15976

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/optiondefs.h b/src/optiondefs.h
index 96c30e2..97fc4d4 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -54,6 +54,7 @@
 #define PV_CPT		OPT_BUF(BV_CPT)
 #define PV_DICT		OPT_BOTH(OPT_BUF(BV_DICT))
 #define PV_TSR		OPT_BOTH(OPT_BUF(BV_TSR))
+#define PV_FFU		OPT_BOTH(OPT_BUF(BV_FFU))
 #define PV_CSL		OPT_BUF(BV_CSL)
 #ifdef FEAT_COMPL_FUNC
 # define PV_CFU		OPT_BUF(BV_CFU)
@@ -74,7 +75,6 @@
 #define PV_FP		OPT_BOTH(OPT_BUF(BV_FP))
 #ifdef FEAT_EVAL
 # define PV_FEX		OPT_BUF(BV_FEX)
-# define PV_FEXPR	OPT_BOTH(OPT_BUF(BV_FEXPR))
 #endif
 #define PV_FF		OPT_BUF(BV_FF)
 #define PV_FLP		OPT_BUF(BV_FLP)
@@ -959,9 +959,10 @@
 			    {(char_u *)"vert:|,fold:-,eob:~,lastline:@",
 								  (char_u *)0L}
 			    SCTX_INIT},
-    {"findexpr",   "fexpr", P_STRING|P_ALLOCED|P_VI_DEF|P_VIM|P_SECURE,
-#if defined(FEAT_EVAL)
-			    (char_u *)&p_fexpr, PV_FEXPR, did_set_optexpr, NULL,
+    {"findfunc", "ffu",     P_STRING|P_ALLOCED|P_VI_DEF|P_SECURE|P_FUNC,
+#ifdef FEAT_EVAL
+			    (char_u *)&p_ffu, PV_FFU,
+			    did_set_findfunc, NULL,
 			    {(char_u *)"", (char_u *)0L}
 #else
 			    (char_u *)NULL, PV_NONE, NULL, NULL,