Trivial fixes to grammar, spelling, whitespace

ivl_target.h

@@ -2013,7 +2013,7 @@ extern unsigned ivl_stmt_lineno(ivl_statement_t net);
  * is the compressed operator used it statements like this:
  *      foo += <expr>
  * The ivl_stmt_opcode() returns null (0) if this is not a compressed
- * assignment statment.
+ * assignment statement.
  *
  * - IVL_ST_CASSIGN
  * This reflects a procedural continuous assignment to an l-value. The

vpi/vhdl_table.c

@@ -104,7 +104,7 @@ static PLI_INT32 ivlh_attribute_event_compiletf(ICARUS_VPI_CONST PLI_BYTE8*name)
       vpi_register_cb(&cb);
       vpi_put_userdata(sys, mon);
 
-	/* Check that there are no more then one argument. */
+	/* Check that there is no more than one argument. */
       arg = vpi_scan(argv);
       if (arg != 0) {
 	    vpi_printf("ERROR: %s:%d: ", vpi_get_str(vpiFile, sys),

vvp/vvp_net_sig.cc

@@ -46,7 +46,7 @@ template <class T> vvp_net_fil_t::prop_t vvp_net_fil_t::filter_mask_(const T&val
       if (!test_force_mask_is_zero()) {
 	      // Some bits are being forced. Go through the
 	      // force_mask_ and force value to see which bits are
-	      // propogated and which are kept from the forced
+	      // propagated and which are kept from the forced
 	      // value. Update the filter with the filtered result and
 	      // return REPL to indicate that some bits have changed,
 	      // or STOP if no bits change.