JSC::Yarr::YarrGenerator<>::initCallFrame creates odd stack frame

When m_pattern.m_body->m_callFrameSize is odd then JSC::Yarr::YarrGenerator<>::initCallFrame creates an unaligned stack pointer on aarch64, causing it to crash in JIT code.

Thread 1 "plasmashell" received signal SIGBUS, Bus error.
0x0000ffffb7faa35c in ?? ()
(gdb) bt
#0 0x0000ffffb7faa35c in ?? ()
#1 0x0000ffffffffd858 in ?? ()
#2 0x00000000005eeec0 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) x/i $pc
=> 0xffffb7faa35c: stur x5, [sp]
(gdb) i reg sp
sp 0xffffffffd6d8 0xffffffffd6d8
(gdb) x/i $lr
0xffffb704c890 <QV4::RegExp::match(QString const&, int, unsigned int*)+4064>:
mov w24, w0