tst-sigaltstack.so fails on aarch64

[wkozaczuk]

OSv v0.55.0-292-g6dec325e
eth0: 192.168.122.15
Booted up in 85.72 ms
Cmdline: /tests/tst-sigaltstack.so
Assertion failed: !(ef->spsr & processor::daif_i) (arch/aarch64/mmu.cc: page_fault: 47)

[backtrace]
0x00000000400e8f70 <__assert_fail+32>
0x000000004020baf0 <page_fault+188>
0x000000004020b828 <???+1075886120>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
0x000010000002128c <???+135820>
...

I think that mainly it fails due to the lack of signals support on aarch64 (see #1154) but there may also be caused by the lack of the "dedicated stack" support.