Add test for code generation of sub-register field extraction

tests/test/cg/tbytetypecast.pp

@@ -0,0 +1,75 @@
+{ Test to check code generation problem for powerpc64 CPU } 
+{ Related to commit 35604b0926 PM }
+
+var
+  HasError : boolean;
+  ErrorCount : longint;
+
+procedure error(i : longint);
+
+begin
+  writeln('Error at pos ',i);
+  HasError:=true;
+  inc(ErrorCount);
+end;
+
+type
+  TRecord = record
+    w1,w2,w3,w4 : word;
+  end;
+
+var
+  w1, w2 : word;
+  b1, b2 : byte;
+  rec : TRecord;
+
+function getrec : TRecord;
+  begin
+    getrec:=rec;
+  end;
+
+begin
+  HasError:=false;
+  ErrorCount:=0;
+  b1:=$57;
+  w1:=$2D57;
+  b2:=$E3;
+  w2:=$ABE3;
+  if (byte(w1)<>b1) then
+    error(1);
+  if (byte(w2)<>b2) then
+    error(2);
+  rec.w1:=w1;
+
+  if (byte(rec.w1)<>b1) then
+    error(3);
+  if (rec.w1=b1) then
+    error(4);
+  if (byte(getrec.w1)<>b1) then
+    error(5);
+  if (getrec.w1<>w1) then
+    error(6);
+  rec.w1:=$1234;
+  rec.w2:=w2;
+  rec.w3:=w1;
+  if (byte(rec.w2)<>b2) then
+    error(7);
+  if (rec.w2=b2) then
+    error(8);
+  if (byte(getrec.w2)<>b2) then
+    error(9);
+  if (getrec.w2<>w2) then
+    error(10);
+  if (byte(rec.w3)<>b1) then
+    error(11);
+  if (rec.w3=b1) then
+    error(12);
+  if (byte(getrec.w3)<>b1) then
+    error(13);
+  if (getrec.w3<>w1) then
+    error(14);
+  if ErrorCount=0 then
+    writeln('Test completed without error')
+  else
+    halt(ErrorCount);
+end.