patch 8.2.3970: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 0a07edb..313073c 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -4660,7 +4660,7 @@
 
 		if ((long)(newsize >> 10) >= p_mmp)
 		{
-		    emsg(_(e_maxmempat));
+		    emsg(_(e_pattern_uses_more_memory_than_maxmempattern));
 		    --depth;
 		    return NULL;
 		}
@@ -5002,7 +5002,7 @@
 
 	    if ((long)(newsize >> 10) >= p_mmp)
 	    {
-		emsg(_(e_maxmempat));
+		emsg(_(e_pattern_uses_more_memory_than_maxmempattern));
 		return NULL;
 	    }
 	    newl = alloc(newsize);