* 128-bit integer multiplication with overflow
* more instruction encodings used by std inline asm
* implement the `try_ptr` air instruction
* follow correct stack frame abi
* enable full panic handler
* enable stack traces
This reverts commit 0c99ba1eab63865592bb084feb271cd4e4b0357e, reversing
changes made to 5f92b070bf284f1493b1b5d433dd3adde2f46727.
This caused a CI failure when it landed in master branch due to a
128-bit `@byteSwap` in std.mem.
Now that allocator.resize() is allowed to fail, programs may wish to
test code paths that handle resize() failure. The simplest way to do
this now is to replace the vtable of the testing allocator with one
that uses Allocator.noResize for the 'resize' function pointer.
An alternative way to support this testing capability is to augment the
FailingAllocator (which is already useful for testing allocation failure
scenarios) to intentionally fail on calls to resize(). To do this, add a
'resize_fail_index' parameter to the FailingAllocator that causes
resize() to fail after the given number of calls.
