Removed compatibility with "= exp" in the REPL

lua.c

@@ -565,10 +565,7 @@ static int pushline (lua_State *L, int firstline) {
   l = strlen(b);
   if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */
     b[--l] = '\0';  /* remove it */
-  if (firstline && b[0] == '=')  /* for compatibility with 5.2, ... */
-    lua_pushfstring(L, "return %s", b + 1);  /* change '=' to 'return' */
-  else
-    lua_pushlstring(L, b, l);
+  lua_pushlstring(L, b, l);
   lua_freeline(b);
   return 1;
 }

testes/main.lua

@@ -345,7 +345,7 @@ a]]
 RUN([[lua -e"_PROMPT='' _PROMPT2=''" -i < %s > %s]], prog, out)
 checkprogout("6\n10\n10\n\n")
 
-prepfile("a = [[b\nc\nd\ne]]\n=a")
+prepfile("a = [[b\nc\nd\ne]]\na")
 RUN([[lua -e"_PROMPT='' _PROMPT2=''" -i < %s > %s]], prog, out)
 checkprogout("b\nc\nd\ne\n\n")