Request for reviews (S): 6910664: C2: java/util/Arrays/Sorting.java fails with DeoptimizeALot flag

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/6910664/webrev.02

Fixed 6910664: C2: java/util/Arrays/Sorting.java fails with DeoptimizeALot flag

Problem:
The test has several java float locals and use XMM registers in debug info.
But the code which restore these values during deoptimization was not
updated for XMM registers usage. It assumes that float values were converted
to double on stack as it was before SSE hardware when FPU was used.

Solution:
Add platform specific method to get float stack value from compiled frame.

Reviewed by:

Fix verified (y/n): y, test with -XX:UseSSE=0|1|2

Other testing:
JPRT