Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r259005, r259092:

gcc: Add -flax-vector-conversions
gcc: new fvisibility-ms-compat option

These are useful for compatibility with newwer gcc and clang.

Obtained from: gcc 4.3 (rev. 120572, 120688, 126088; GPLv2)

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

This commit was generated by cvs2svn to compensate for changes in r169689,
which included commits to RCS files with non-trunk default branches.

GCC 4.2.0 release.

Gcc 3.4.4 release.

Gcc 3.4.2 20040728.

Gcc 3.3.1-pre as of 2003-07-11.