JIT: Performance fix for const doubles

Some recent Arm processors take a performance hit when
creating a floating point double by loading it as a pair of singles.
Legacy code to support soft floating point doubles as a pair of core
registers loaded double immediates in this way.

With the CL, we handle double immediates as a single unit.

(cherry-pick of c8129911e598ad0ca8d7b31012444ab6ce8bce45.)

Change-Id: Ic1512e34bfd233a6f5ffd58ce843965adbbad875
Use ALOGE rather than SLOGE for mountEmulatedStorage failures.

Otherwise the actual failure isn't in logcat, and all you see there
is the rather confusing:

  E dalvikvm: cannot mountExternalStorage(): Success

Change-Id: I10c96748b5ff5b6c3877312e7bdb2641026b4489