Slightly improve hash function

src/toolsrc/plforth.pla

@@ -683,7 +683,7 @@ def hashname(chars, len)#1
 
   hash = 0
   while len
-    hash = hash + ^chars
+    hash = (hash << 1) ^ ^chars
     chars++
     len--
   loop
@@ -713,19 +713,18 @@ def buildhashtbl#0
 end
 def find(matchchars, matchlen)#1
   word dentry
-  byte i, hash
+  byte i
 
-  hash = hashname(matchchars, matchlen)
+  dentry = hashtbl[hashname(matchchars, matchlen)]
   matchchars--
-  dentry = hashtbl[hash]
   while dentry
     if ^dentry == matchlen
-      for i = 1 to ^dentry
+      for i = matchlen downto 1
         if ^(matchchars + i) <> ^(dentry + i)
           break
         fin
       next
-      if i > ^dentry
+      if i == 0
         return dentry
       fin
     fin
@@ -813,7 +812,6 @@ end
 // Execute code in CFA
 //
 def execword(dentry)#0
-
   when conio:keypressed()
     is $83 // CTRL-C
       getc // Clear KB