* force records with LOC_CONSTANT into memory when they are subscripted

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26630 3ad0048d-3df7-0310-abae-a5850022a9f2
* tests fail if dead values are optimized so disable dead value optimization for the tests

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26631 3ad0048d-3df7-0310-abae-a5850022a9f2
* rbp can be used for normal purpose under certain conditions so it shouldn't interfere with all other registers

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26632 3ad0048d-3df7-0310-abae-a5850022a9f2
+ cs_userbp optimizer switch, so on x86-64 the compiler can make use of rbp if it is not needed as frame pointer

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26633 3ad0048d-3df7-0310-abae-a5850022a9f2