* sqr(real) and sqrt(real): remove typeconv node inserted by initial call processing (see explanation in comments), allowing these functions to be evaluated using precision of argument. In particular, sqrt(single) and sqrt(double) now emit 'sqrtss' and 'sqrtsd' instructions on x86 targets with -Cfsse3. Non-x86 targets already have the necessary support in code generators.
* abs(real): handle the same way as sqrt and sqr, i.e. without casting to bestreal and back.


git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@27808 3ad0048d-3df7-0310-abae-a5850022a9f2