MIR Serialization: Serialize the simple MachineFrameInfo attributes.

This commit serializes the 13 scalar boolean and integer attributes from the
MachineFrameInfo class: IsFrameAddressTaken, IsReturnAddressTaken, HasStackMap,
HasPatchPoint, StackSize, OffsetAdjustment, MaxAlignment, AdjustsStack,
HasCalls, MaxCallFrameSize, HasOpaqueSPAdjustment, HasVAStart, and
HasMustTailInVarArgFunc. These attributes are serialized as part
of the frameInfo YAML mapping, which itself is a part of the machine function's
YAML mapping.

llvm-svn: 241844