[libpng16] test: Move cicp-display-p3_reencoded.png to contrib/testpngs/png-3/

Update the main CMake file and the auxiliary test scripts accordingly.

This is a cherry-pick of commit fe277b7752990be35523832a546aec478437968a
from branch 'libpng18'.

CMakeLists.txt

@@ -804,6 +804,8 @@ if(PNG_TESTS AND PNG_SHARED)
   list(SORT PNGSUITE_PNGS)
   file(GLOB TEST_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/testpngs/*.png")
   list(SORT TEST_PNGS)
+  file(GLOB TEST_PNG3_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/testpngs/png-3/*.png")
+  list(SORT TEST_PNG3_PNGS)
 
   set(PNGTEST_PNG "${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png")
 
@@ -814,9 +816,9 @@ if(PNG_TESTS AND PNG_SHARED)
                COMMAND pngtest
                FILES "${PNGTEST_PNG}")
 
-  png_add_test(NAME pngtest-cicp
+  png_add_test(NAME pngtest-png-3
                COMMAND pngtest
-               FILES "${CMAKE_CURRENT_SOURCE_DIR}/cicp-display-p3_reencoded.png")
+               FILES "${TEST_PNG3_PNGS}")
 
   add_executable(pngvalid ${pngvalid_sources})
   target_link_libraries(pngvalid PRIVATE png_shared)

tests/pngtest-all

@@ -24,6 +24,9 @@ TEST(){
 # The "standard" test
 TEST --strict "${srcdir}"/pngtest.png
 
+# PNG-3 tests
+TEST --strict "${srcdir}"/contrib/testpngs/png-3/*.png
+
 # Various crashers
 # Use --relaxed because some come from fuzzers that don't maintain CRCs
 TEST --relaxed "${srcdir}"/contrib/testpngs/crashers/badcrc.png