Merge branch 'ty/migrate-trust-executable-bit' into jch

The 'trust_executable_bit' (coming from the 'core.filemode' configuration) has been migrated into 'struct repo_config_values' to tie it to a specific repository instance. * ty/migrate-trust-executable-bit: environment: move has_symlinks into repo_config_values environment: move trust_executable_bit into repo_config_values read-cache: pass 'repo' to 'ce_mode_from_stat()' read-cache: remove redundant extern declarations