Extract the logic that computes ACC_SYNTHETIC flag for deprecated
declarations, and use `DeprecationResolver` as the old backend does in
`DescriptorAsmUtil.getCommonCallableFlags`. Creating IR-based
descriptors for each function to pass it there is a bit costly though,
so as a small optimization, use `allOverridden` to check if anything in
the method hierarchy is deprecated.
Also optimize `allOverridden` for the case of linear inheritance which
is far more common.
#KT-43199 Fixed
Alexander Udalov
0e91d3fcb0