Update the status of a few more C DRs

This includes tests for DR085 and DR259.

clang/test/C/drs/dr0xx.c

@@ -70,6 +70,9 @@
  * WG14 DR080: yes
  * Merging of string constants
  *
+ * WG14 DR085: yes
+ * Returning from main
+ *
  * WG14 DR086: yes
  * Object-like macros in system headers
  *

clang/test/C/drs/dr259.c

@@ -0,0 +1,21 @@
+/* RUN: %clang_cc1 -std=c89 -E -verify %s | FileCheck %s
+   RUN: %clang_cc1 -std=c99 -E -verify %s | FileCheck %s
+   RUN: %clang_cc1 -std=c11 -E -verify %s | FileCheck %s
+   RUN: %clang_cc1 -std=c17 -E -verify %s | FileCheck %s
+   RUN: %clang_cc1 -std=c2x -E -verify %s | FileCheck %s
+ */
+
+/* expected-no-diagnostics */
+
+/* WG14 DR259: yes
+ * Macro invocations with no arguments
+ */
+#define m0() replacement
+#define m1(x) begin x end
+
+m0() m1()
+
+/*
+CHECK: replacement begin end
+*/
+

clang/www/c_dr_status.html

@@ -565,7 +565,7 @@ conformance.</p>
     <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_085.html">85</a></td>
     <td>C89</td>
     <td>Returning from main</td>
-    <td class="unknown" align="center">Unknown</td>
+    <td class="full" align="center">Yes</td>
   </tr>
   <tr id="86">
     <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_086.html">86</a></td>
@@ -1488,7 +1488,7 @@ conformance.</p>
     <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_259.htm">259</a></td>
     <td>NAD</td>
     <td>Macro invocations with no arguments</td>
-    <td class="unknown" align="center">Unknown</td>
+    <td class="full" align="center">Yes</td>
   </tr>
   <tr id="260">
     <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_260.htm">260</a></td>