Renamed testcases from "*.sv" to "*.v"

ivtest/ivltests/br_gh823a.v

@@ -1,4 +1,4 @@
-// testcase for Issue #823 on Github
+// Testcase for Issue #823 on Github
 
 module test;
   struct packed {logic a;} s;

ivtest/ivltests/br_gh840b.v

@@ -1,8 +1,8 @@
-// Testcase for Issue #840 on Github
+// Testchase for #840 on Github
 
 module test;
   logic [1:0][1:0] a;
-  logic [1:0][1:0] b;
+  logic [2:0][1:0] b;
   generate
     for(genvar i=0;i<3;i++)
       assign b[i] = a[i];