Packages referencing variables defined in setup_toolchain such as CC, CXX,
AR, CFLAGS, LDFLAGS, HOST_CC etc. etc. must only reference these variables in
pre_build()/pre_configure()/pre_make() etc. functions, as the variables will not
be available when the package is sourced, but will be available after the call
to setup_toolchain() from scripts/build.
- replace strip_lto/strip_gold (only allowed to disable)
- add flag for PIC feature
- add flag to stop build parallel
- add support for hardening option (initial copy from debian 9)
All build parameters, are added in setup_toolchain.
`PKG_[FLAG]_[HOST/TARGET]_ENABLED` variable is introduced for checking the flag (yes/no) in the package.mk
Thanks to @MilhouseVH, for support and fixing
