build: `oldtest` target: TEST_FILE, NVIM_PRG (#6098)

- Add support for TEST_FILE to the `oldtest` target, for consistency
  with the busted/lua tests.
  Caveat: with the busted/lua tests TEST_FILE takes a full path, whereas
  for `oldtest` it must be "test_foo.res".
- Add support for NVIM_PRG, again so that all test-related targets are
  consistent.
- Use consistent name for NVIM_PRG. But still need to support NVIM_PROG
  for QuickBuild CI.

Note: The `oldtest` target is driven by the top-level Makefile, because
it requires a TTY. CMake 3.2 added a USES_TERMINAL flag to
add_custom_target(). But we support CMake 2.8...

    add_custom_target(oldtest
      COMMAND make clean
      COMMAND make NVIM_PRG=$<TARGET_FILE:nvim> $ENV{MAKEOVERRIDES}
      DEPENDS nvim
      WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/src/nvim/testdir"
      USES_TERMINAL true
    )

1 files changed, 4 insertions, 4 deletions

diff --git a/src/nvim/testdir/Makefile b/src/nvim/testdir/Makefile
index 55ee653a1e..799eeed7d8 100644
--- a/src/nvim/testdir/Makefile
+++ b/src/nvim/testdir/Makefile
@@ -4,10 +4,10 @@
 
 export SHELL := sh
 
-VIMPROG := ../../../build/bin/nvim
+VIMPROG ?= $(NVIM_PRG)
 SCRIPTSOURCE := ../../../runtime
 
-SCRIPTS := \
+SCRIPTS ?= \
            test13.out             \
            test14.out             \
            test17.out             \
@@ -25,9 +25,9 @@ SCRIPTS := \
            test79.out             \
            test_marks.out         \
 
-# Tests using runtest.vim.vim.
+# Tests using runtest.vim.
 # Keep test_alot*.res as the last one, sort the others.
-NEW_TESTS = \
+NEW_TESTS ?= \
 	    test_bufwintabinfo.res \
 	    test_cmdline.res \
 	    test_cscope.res \