Request for reviews (S): 7006044: materialize cheap non-oop pointers on 64-bit SPARC

[Christian Thalinger]

http://cr.openjdk.java.net/~twisti/7006044/webrev.01/

7006044: materialize cheap non-oop pointers on 64-bit SPARC
Summary: After 6961690 we load non-oop pointers for the constant table which could easily be materialized in a few instructions.
Reviewed-by:

After 6961690 we load non-oop pointers for the constant table which
could easily be materialized in a few instructions.  This happens
commonly with the init of the header word in an allocation.

Tested with runThese, DaCapo and CTW on a T2+.

For a whole CTW run 165k non-oop loads were emitted, of which 47%
could be materialized.

Additionally I fixed a bug in MacroAssembler::size_of_sethi.  The
worst case returned the number of instructions while all other returns
returned the number of bytes of code used by the instructions.  I
changed all size_of_* functions to return the number of instructions
and to better reflect what these functions return I renamed them to
insts_for_*.