[PATCH 0/2] scripts: dtc cpp flags via response file, GNU Make 4.0 cleanup

This series fixes a dtc build failure on long source paths and cleans
up the now-dead GNU Make 3.x compatibility code in the top-level
Makefile.

Patch 1 fixes a build failure where a long $(srctree) makes the
HOSTCC/CPP command line for cmd_dtc/cmd_dtco exceed the shell's
argument limit, by writing dtc_cpp_flags to a response file and
passing @file instead. This relies on the $(file ...) function,
which requires GNU Make >= 4.0.

Patch 2 raises the enforced minimum GNU Make version to 4.0, adding
an explicit "GNU Make >= 4.0 is required" check to the top-level
Makefile and dropping the now-dead GNU Make 3.x compatibility
branches.

Suraj Kakade (2):
  scripts: pass dtc cpp flags via a GCC response file
  Makefile: drop GNU Make < 4.0 compatibility code

 Makefile             | 20 +++++---------------
 scripts/Makefile.lib |  7 +++++--
 2 files changed, 10 insertions(+), 17 deletions(-)

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2.43.7