renamed Allocation::check_defined_and_ptr to Allocation::check_init_and_ptr

renamed Allocation::check_defined_and_ptr to Allocation::check_init_and_ptr

in src/librustc_middle/mir/interpret/allocation.rs

renamed Allocation::is_defined and Allocation::check_defined, fixed documentation

renamed Allocation::is_defined and Allocation::check_defined to is_init and check_init respectively.

Fixed documentation so it correctly refers to "initialization" instead of "defined"-ness

renamed Allocation::mark_definedness

renamed Allocation::mark_definedness to Allocation::mark_init

Renamed new_state parameter in Allocation::mark_init

Renamed new_state to is_init, as the latter is more descriptive.

renamed functions in AllocationDefinedness

renamed AllocationDefinedness::all_bytes_undef and AllocationDefinedness::mark_compressed_undef_range to no_bytes_init and mark_compressed_init_range respectively.

renamed AllocationDefinedness to InitMaskCompressed

renamed Immediate::to_scalar_or_undef

renamed to to_scalar_or_uninit

fixed comment references to "undef"

Changed comments referring to "undef" and "definedness" to "initialization" and "initialization state" in src/librustc_mir/interpret/memory.rs and src/librustc_middle/mir/interpret/allocation.rs

changed references to "undef" in comments and a variable

Changed some comments referring to "undef" to use "uninitialized" instead. Also changed a variable from "undef_end" to "uninit_end".
All changes were made within src/librustc_middle/mir/interpret/allocation.rs.

Changed more comments referring to undef

Changed comments to use "uninitialized" instead of "undef" in src/librustc_middle/mir/interpret/allocation.rs.