The build-infra project is starting to move into jdk8. For the hotspot build to stay compatible with the changes, key hotspot makefiles need to add an optional include statement:
In the new build system, the spec file is generated by configure and contains the configuration for the build. Only a handfull of files need to add this line.
In addition to including the spec file, some variables need to be changed to only be set conditinally so that a value from the spec file takes precedence. These are: CC, CXX, CPP, AS, MCS, STRIP, NM, NAWK (and for windows RC and MT). The hotspot makefiles should check each variable if it's already set or if it has a gnumake default value.