Reorganize test dir to ensure test of installed pkg

tests/test_read_fanin/regblock.rdl

@@ -0,0 +1,10 @@
+addrmap top #(
+    longint N_REGS = 1,
+    longint REGWIDTH = 32
+) {
+    reg reg_t {
+        regwidth = REGWIDTH;
+        field {sw=rw; hw=na;} f[REGWIDTH] = 1;
+    };
+    reg_t regs[N_REGS];
+};