Merge branch 'refactoring/kernel/CombineTypes' into 'master'

Changelog

src/kernel_internals/typing/cabs2cil.ml

src/kernel_internals/typing/mergecil.ml

src/kernel_services/ast_queries/cil.ml

src/kernel_services/ast_queries/cil.mli

src/kernel_services/plugin_entry_points/kernel.ml

src/kernel_services/plugin_entry_points/kernel.mli

tests/cil/oracle/cpu_a.res.oracle

tests/cil/oracle/cpu_b.res.oracle

tests/misc/oracle/audit-out.json

tests/misc/oracle/bts0990_link.res.oracle

tests/syntax/oracle/incompatible_qualifiers.1.res.oracle

tests/syntax/oracle/inconsistent_decl.0.res.oracle

tests/syntax/oracle/inconsistent_decl.1.res.oracle