* Fix segfault due to b64 encoding
Prior to this patch, bconst.b64 encoded its instruction with a 32-bit immediate that caused improper decoding of the MOV instruction; instead, use a REX prefix and rely on zero-extension of the immediate. Fixes#911.
In talking to @sunfishcode, he preferred to avoid the confusion of more ISA predicates by eliminating SSE2. SSE2 was released with the Pentium 4 in 2000 so it is unlikely that current CPUs would have SIMD enabled and not have this feature. I tried to note the SSE2-specific instructions with comments in the code.
-Add resumable_trap, safepoint, isnull, and null instructions
-Add Stackmap struct and StackmapSink trait
Co-authored-by: Mir Ahmed <mirahmed753@gmail.com>
Co-authored-by: Dan Gohman <sunfish@mozilla.com>
This makes non-legalized jump table instructions operate on operands with
pointer-sized types. This means we need to extend smaller types into the
pointer-sized operand, when the two don't match.
