Add br_gh800 test

This is a test for github issue#800. This should work on all platforms,
but Windows seems weird. The issue seems to be with Windows comparing
gold files with CR-LF weirdly, so make all the tests internal.

ivtest/ivltests/br_gh800.v

@@ -0,0 +1,52 @@
+
+// br_gh800 (github Issue #800)
+module AssignLiterals;
+   initial begin
+      string s;
+
+      // Note that the \0 in this string literal assigned to the string
+      // must disappear, leaving "AB" what is actually assigned to the
+      // string. See IEEE Std 1800-2017: 6.16 String data type.
+      s = "A\0B";
+      $display("1. '%s' len=%1d hex=%02h%02h%02h",s,s.len(), s[0], s[1], s[2]);
+      if (s.len() != 2 || s != "AB" || s[0] !== 'h41 || s[1] !== 'h42) begin
+	 $display("FAILED");
+	 $finish;
+      end
+
+      s = "A\015\12B";
+      $display("2. len=%1d hex=%02h%02h%02h%02h",s.len(), s[0], s[1], s[2], s[3]);
+      if (s.len() != 4 || s[0] !== 'h41 || s[1] !== 'h0d
+	  || s[2] !== 'h0a || s[3] !== 'h42) begin
+	 $display("FAILED");
+	 $finish;
+      end
+
+      s = {"A","\015","\012","B"};
+      $display("3. len=%1d hex=%02h%02h%02h%02h",s.len(), s[0], s[1], s[2], s[3]);
+      if (s.len() != 4 || s[0] !== 'h41 || s[1] !== 'h0d
+	  || s[2] !== 'h0a || s[3] !== 'h42) begin
+	 $display("FAILED");
+	 $finish;
+      end
+
+      s = "A\170\171B";
+      $display("4. '%s' len=%1d hex=%02h%02h%02h%02h",s,s.len(),
+	       s[0], s[1], s[2], s[3]);
+      if (s.len() != 4 || s[0] !== 'h41 || s[1] !== 'h78 || s[2] !== 'h79
+	  || s[3] !== 'h42) begin
+	 $display("FAILED");
+	 $finish;
+      end
+
+      s = {"A",8'o15,8'o12,"\012","B"};
+      $display("5. len=%1d hex=%02h%02h%02h%02h%02h",s.len(), s[0], s[1], s[2], s[3], s[4]);
+      if (s.len() != 5 || s[0] !== 'h41 || s[1] !== 'h0d
+	  || s[2] !== 'h0a || s[3] !== 'h0a || s[4] !== 'h42) begin
+	 $display("FAILED");
+	 $finish;
+      end
+
+      $display("PASSED");
+    end
+endmodule

ivtest/regress-sv.list

@@ -228,6 +228,7 @@ br_gh699		CE,-g2009		ivltests
 br_gh756		normal,-g2009		ivltests
 br_gh782a		normal,-g2009		ivltests gold=br_gh782a.gold
 br_gh782b		normal,-g2009		ivltests gold=br_gh782b.gold
+br_gh800		normal,-g2009		ivltests
 br_gh801		normal,-g2009		ivltests
 br_gh801b		normal,-g2009		ivltests
 br_ml20171017		normal,-g2009		ivltests