Use `full-core` gembox for `clang-asan` configuration.
For better coverage.
MODIFY
build_config/clang-asan.rb
build_config/clang-asan.rb
MRuby::Build.new do |conf|
conf.toolchain :clang
# include the GEM box
- conf.gembox 'default'
+ conf.gembox 'full-core'
# Turn on `enable_debug` for better debugging
conf.enable_sanitizer "address,undefined"

Use `full-core` gembox for `clang-asan` configuration.

For better coverage.