* Added test for #41270 register allocation error

tests/webtbs/tw41270.pp

@@ -0,0 +1,39 @@
+program tw41270;
+{$mode objfpc}
+
+{$OPTIMIZATION OFF}
+{$OPTIMIZATION REGVAR}
+
+var
+  arr: array [0..3] of Double;
+
+procedure mdtgen(n: Integer; var alu: Double);
+var
+  nsr, ind, i, j: Integer;
+  sumrowi, h, s: Double;
+  palu, t, pp: PDouble;
+  singular : Boolean;
+begin
+  palu := @alu;
+  pp := @alu;
+  nsr := n*sizeof(Double);
+  getmem(t, nsr);
+  for i:=1 to n do
+  begin
+    for j:=1 to n do;
+    ind:=1;
+    h := random;
+    singular := false;
+    sumrowi := palu[ind];
+  end;
+
+  s:=0.0;
+  i:=0;
+  h:=s+palu[i+i+0]; // <- ACCESS VIOLATION:  addsd xmm0,[rax*8+rax]
+  freemem(t, nsr)
+end;
+
+begin
+  mdtgen(2, arr[0]);
+  WriteLn('ok');
+end.