RFR: 8251152: ARM32: jtreg c2 Test8202414 test crash

[Filipp Zhinkin]

Hi,

Test8202414 crashes on ARM32 while writing to memory using an unaligned
address.
ARM32 supports unaligned memory accesses for some load/store instructions
under certain conditions, but LDRD (which is used when we're calling
Unsafe::putLong) is always causing alignment fault when called with an
unaligned address [1].

The fix is simply skipping the test execution if a platform does not
support unaligned memory accesses.

Bug: https://bugs.openjdk.java.net/browse/JDK-8251152
Webrev: http://cr.openjdk.java.net/~bulasevich/fzhinkin/8251152/webrev.0/

[1] ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition, §A3.2.1
Unaligned data access https://developer.arm.com/documentation/ddi0406/cd

Thanks,
Filipp.