[PATCH htdocs] bugs: Link to all 'Porting to' docs in 'Common problems when upgrading ...'

[Sam James]

Suggested by Andrew Pinski. I think it makes sense to have it in here even
if perhaps a bit verbose, because we really try to tell bug reporters to
read the page properly.

This could also be a table.
---
 htdocs/bugs/index.html | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/htdocs/bugs/index.html b/htdocs/bugs/index.html
index 99d19095..910ed868 100644
--- a/htdocs/bugs/index.html
+++ b/htdocs/bugs/index.html
@@ -627,6 +627,30 @@ changed the parser rules so that <code>&lt;::</code> works 
as expected.
 
 <h3 id="upgrading">Common problems when upgrading the compiler</h3>
 
+<p>
+GCC maintains a 'Porting to' resource for new versions of the compiler:
+</p>
+<ul>
+  <li><a href="https://gcc.gnu.org/gcc-15/porting_to.html";>GCC 15</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-14/porting_to.html";>GCC 14</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-13/porting_to.html";>GCC 13</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-12/porting_to.html";>GCC 12</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-11/porting_to.html";>GCC 11</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-10/porting_to.html";>GCC 10</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-9/porting_to.html";>GCC 9</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-8/porting_to.html";>GCC 8</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-7/porting_to.html";>GCC 7</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-6/porting_to.html";>GCC 6</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-5/porting_to.html";>GCC 5</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-4.9/porting_to.html";>GCC 4.9</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-4.8/porting_to.html";>GCC 4.8</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-4.7/porting_to.html";>GCC 4.7</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-4.6/porting_to.html";>GCC 4.6</a></li>
+  <!-- no such doc for 4.5 -->
+  <li><a href="https://gcc.gnu.org/gcc-4.4/porting_to.html";>GCC 4.4</a></li>
+  <li><a href="https://gcc.gnu.org/gcc-4.3/porting_to.html";>GCC 4.3</a></li>
+</ul>
+
 <h4>ABI changes</h4>
 
 <p>The C++ application binary interface (ABI) consists of two
-- 
2.48.1