Correct for 115-native-bridge hard-coded x86/x86_64 signal handling values

Added inline assembly to ensure that the instruction causing a segfault
in x86/x86_64 for the 115-native-bridge test always has a size of 3 bytes,
in response to a bug that caused the test to fail when this instruction
had variable sizes.

Bug: 22876261
Change-Id: I296e623f170fd1925919bedf913c569a6563e3dc