DOC: install: mention the common strict-aliasing warning on older compilers
In the errors and warnings section about common issues, it's useful to
mention the strict-aliasing warning that was happening with gcc-4.4 that
may still be found on old systems, especially since it will probably take
ages to build there and the warning is harmless.
diff --git a/INSTALL b/INSTALL
index ca47aa8..e8b36e0 100644
--- a/INSTALL
+++ b/INSTALL
@@ -446,6 +446,10 @@
not support QUIC. Either disable QUIC with "USE_QUIC=" or use any
other supported compatible library.
+ - many "dereferencing pointer 'sa.985' does break strict-aliasing rules"
+ => these warnings happen on old compilers (typically gcc-4.4), and may
+ safely be ignored; newer ones are better on these.
+
4.11) QUIC
----------