Merge branch 'subdir-objects-work'

* subdir-objects-work:
  depend: reduce code duplication, de-uglify make verbose output
  depend: prefer $(...) over `...` in Cygwin-specific recipes
  depend: reduce code duplication
  depend: a preparatory refactoring
  depend: refactor and remove code duplication
  Automake::Language: drop unused fields 'compile_flag' and 'output_flag'
  depend: assume '-c' compiler flag always means to produce object files
  depend: assume we can always pass '-o' to the C compiler
  cleanup: having subdir-objects mandatory allow us some simplifications
  subdir-objects: enable unconditionally

diff --cc NEWS
Simple merge

diff --cc t/compile_f_c_cxx.sh
index a0b0e216f17941aaa257697595987a480cd1ba54,4b9189d61eecbecb7f909626fc97deb45df9dacc..4b9189d61eecbecb7f909626fc97deb45df9dacc
mode 100644,100755..100644
--- 1/t/compile_f_c_cxx.sh
--- 2/t/compile_f_c_cxx.sh
+++ b/t/compile_f_c_cxx.sh

diff --cc t/cscope.tap
index 9dbe01b2ff0b84af25fe5d724dd0f5490c3e9d3c,29feec2284d8c34e0c0ffcc62d45899e62bb6a58..29feec2284d8c34e0c0ffcc62d45899e62bb6a58
mode 100644,100755..100644
--- 1/t/cscope.tap
--- 2/t/cscope.tap
+++ b/t/cscope.tap

diff --cc t/depcomp8a.sh
index d6c73edb7335f3e40239b71dea7f4dce84668e74,4cb545b97aa98955c7a3aa256f69ad7d52ed48b7..4cb545b97aa98955c7a3aa256f69ad7d52ed48b7
mode 100644,100755..100644
--- 1/t/depcomp8a.sh
--- 2/t/depcomp8a.sh
+++ b/t/depcomp8a.sh

diff --cc t/depcomp8b.sh
index 879ee1c0d4e5f5848b2e23701de2ed73adadc258,c06c3c17a6193b39136a81b4b90e0fdf3cfb4e1c..c06c3c17a6193b39136a81b4b90e0fdf3cfb4e1c
mode 100644,100755..100644
--- 1/t/depcomp8b.sh
--- 2/t/depcomp8b.sh
+++ b/t/depcomp8b.sh

diff --cc t/fort2.sh
index d6144529624898154746ccb074340a2c90e8a0e7,bed0323682e4104f92cc748ed860e41eab1a864d..bed0323682e4104f92cc748ed860e41eab1a864d
mode 100644,100755..100644
--- 1/t/fort2.sh
--- 2/t/fort2.sh
+++ b/t/fort2.sh

diff --cc t/fort4.sh
index 2ef27abebbb3d0941d39ec860efd5dc64bf79166,2d01ee46d49cfb5cd64f98e181769b4998a5d4e0..2d01ee46d49cfb5cd64f98e181769b4998a5d4e0
mode 100644,100755..100644
--- 1/t/fort4.sh
--- 2/t/fort4.sh
+++ b/t/fort4.sh

diff --cc t/fort5.sh
index 7b9991b969211c89e9f796ed18310580b001d6f3,d090f6ffd08ebd79384cfaa33ee8803b3da76000..d090f6ffd08ebd79384cfaa33ee8803b3da76000
mode 100644,100755..100644
--- 1/t/fort5.sh
--- 2/t/fort5.sh
+++ b/t/fort5.sh

diff --cc t/gcj.sh
index 3de295363f960ebff1c58b148d118af64da1102f,3b058a5c2893888abf02573a65a5dcde413687eb..3b058a5c2893888abf02573a65a5dcde413687eb
mode 100644,100755..100644
--- 1/t/gcj.sh
--- 2/t/gcj.sh
+++ b/t/gcj.sh

diff --cc t/lex-line.sh
index 258f6af56dea8845681059e93b9f79b12a8bb36e,ec9fcd3f71666565852705bc04d0fde7d6dbe9db..ec9fcd3f71666565852705bc04d0fde7d6dbe9db
mode 100644,100755..100644
--- 1/t/lex-line.sh
--- 2/t/lex-line.sh
+++ b/t/lex-line.sh

diff --cc t/libobj20b.sh
index f86a46c157a2af40ec52ddb070e3f0ef4f08de14,70442dd17fc160f1e7be9c90ec1bfa25bcbe417a..70442dd17fc160f1e7be9c90ec1bfa25bcbe417a
mode 100644,100755..100644
--- 1/t/libobj20b.sh
--- 2/t/libobj20b.sh
+++ b/t/libobj20b.sh

diff --cc t/libobj20c.sh
index 7b918021e4482955cbbb555732970d003a8da6ff,5f8eb688d6239fccc5f8f1a060d3f134f88c5c1f..5f8eb688d6239fccc5f8f1a060d3f134f88c5c1f
mode 100644,100755..100644
--- 1/t/libobj20c.sh
--- 2/t/libobj20c.sh
+++ b/t/libobj20c.sh

diff --cc t/libtool3.sh
index 5653280e6ada117a629091ef9cb9b6a0cc1a6230,4f45a39676e5a9e0d7848241915711a3c924853c..4f45a39676e5a9e0d7848241915711a3c924853c
mode 100644,100755..100644
--- 1/t/libtool3.sh
--- 2/t/libtool3.sh
+++ b/t/libtool3.sh

diff --cc t/ltlibsrc.sh
index 8c8098bdb7c9a688577c36e686b38137559329a3,04a029fe71962c2cbd82b92a7ecddff84acc24db..04a029fe71962c2cbd82b92a7ecddff84acc24db
mode 100644,100755..100644
--- 1/t/ltlibsrc.sh
--- 2/t/ltlibsrc.sh
+++ b/t/ltlibsrc.sh

diff --cc t/pr401.sh
index 89094de75ad965dcf5ab393c4027c56222a79a23,090b2e903a308c35cbb510d469b28fc0765b3bc8..090b2e903a308c35cbb510d469b28fc0765b3bc8
mode 100644,100755..100644
--- 1/t/pr401.sh
--- 2/t/pr401.sh
+++ b/t/pr401.sh

diff --cc t/pr401b.sh
index cf7a6988532607f4b9429e90035ddbe152218416,f993108bb04c8967b721c540b504517807762764..f993108bb04c8967b721c540b504517807762764
mode 100644,100755..100644
--- 1/t/pr401b.sh
--- 2/t/pr401b.sh
+++ b/t/pr401b.sh

diff --cc t/pr401c.sh
index 22e58762990a2b8f164512baaf3b5c9315f16c3e,eb2f4fb7b1f75dc1f6c1b4f5498c124f6f374625..eb2f4fb7b1f75dc1f6c1b4f5498c124f6f374625
mode 100644,100755..100644
--- 1/t/pr401c.sh
--- 2/t/pr401c.sh
+++ b/t/pr401c.sh

diff --cc t/silent-nested-vars.sh
index f03204d0b0c524197532117ada4295ae2d72e9b1,08f46fd26dee2eaa8372d67a3c84e7effbd11573..08f46fd26dee2eaa8372d67a3c84e7effbd11573
mode 100644,100755..100644
--- 1/t/silent-nested-vars.sh
--- 2/t/silent-nested-vars.sh
+++ b/t/silent-nested-vars.sh

diff --cc t/subobj.sh
index f595e68ad8ddadbef8051c194612fe56e6108f1b,fa0036803e549af01ae0cfb4dd8440ac20c399e5..fa0036803e549af01ae0cfb4dd8440ac20c399e5
mode 100644,100755..100644
--- 1/t/subobj.sh
--- 2/t/subobj.sh
+++ b/t/subobj.sh

diff --cc t/subpkg-yacc.sh
index 9fc6761907570264143279633212ff407f30b60f,1fe50a5723280513eb257b3b5621694d6bd09b65..1fe50a5723280513eb257b3b5621694d6bd09b65
mode 100644,100755..100644
--- 1/t/subpkg-yacc.sh
--- 2/t/subpkg-yacc.sh
+++ b/t/subpkg-yacc.sh

diff --cc t/subpkg.sh
index f9cdc74e2bb58bf0de2522d9188be29f3bbc2dea,f1e3f2b3a46f1908f9475af4fc667b3f362a39c7..f1e3f2b3a46f1908f9475af4fc667b3f362a39c7
mode 100644,100755..100644
--- 1/t/subpkg.sh
--- 2/t/subpkg.sh
+++ b/t/subpkg.sh

diff --cc t/xsource.sh
index a3fe6e5141cd13f6b9569e5bca6b9ad9c13546ae,70dfd4e742e3b83aa45eddf3fa35cf23c0f7d670..70dfd4e742e3b83aa45eddf3fa35cf23c0f7d670
mode 100644,100755..100644
--- 1/t/xsource.sh
--- 2/t/xsource.sh
+++ b/t/xsource.sh

diff --cc t/yacc-grepping2.sh
index 3c5da22557194dabd7959fe22210c136b5f8f8cc,eb4afeda1a308c2a574747a7f6ebf58ea3510642..eb4afeda1a308c2a574747a7f6ebf58ea3510642
mode 100644,100755..100644
--- 1/t/yacc-grepping2.sh
--- 2/t/yacc-grepping2.sh
+++ b/t/yacc-grepping2.sh

diff --cc t/yacc-line.sh
index b034af36ef67af9b3efd0e9bffd986a75f5810b0,d0c6300465473d3dca53fc2dc6bb22a85846fb56..d0c6300465473d3dca53fc2dc6bb22a85846fb56
mode 100644,100755..100644
--- 1/t/yacc-line.sh
--- 2/t/yacc-line.sh
+++ b/t/yacc-line.sh