rtl: add HashName function based on implementation of Hash() from objpas. It uses case case-insensitive hash generation. This function is added for compatibility with delphi (although it generates different hash in delphi and fpc for same strings). It is also needed for codepage search in hash array.

git-svn-id: trunk@19353 -

rtl/objpas/sysutils/sysansi.inc

@@ -69,3 +69,24 @@ begin
   Result:=StrScan(Str,Chr);
 end;
 
+Function HashName(Name: PAnsiChar): LongWord;
+Var
+  thehash,g,I : LongWord;
+begin
+  thehash:=0;
+  For I:=1 to Length(Name) do { 0 terminated }
+    begin
+      thehash:=thehash shl 4;
+      inc(theHash,Ord(UpCase(Name[i])));
+      g:=thehash and LongWord($f shl 28);
+      if g<>0 then
+        begin
+          thehash:=thehash xor (g shr 24);
+          thehash:=thehash xor g;
+        end;
+    end;
+  If theHash=0 then
+    HashName:=$ffffffff
+  else
+    HashName:=TheHash;
+end;

rtl/objpas/sysutils/sysansih.inc

@@ -25,4 +25,4 @@ function AnsiPos(const substr,s : string) : SizeInt;
 function AnsiStrPos(str,substr : PChar) : PChar;
 function AnsiStrRScan(Str : PChar;Chr : Char) : PChar;
 function AnsiStrScan(Str : PChar;Chr: Char) : PChar;
-
+function HashName(Name: PAnsiChar): LongWord;