Tests/FortranOnly: add a test case for issue #25112

Add a test case for Fortran `OBJECT` libraries providing modules to
consumers.

Tests/FortranOnly/CMakeLists.txt

@@ -184,3 +184,9 @@ if(CMAKE_Fortran_COMPILE_OPTIONS_PREPROCESS_OFF AND
   set_property(TARGET no_preprocess_target PROPERTY Fortran_PREPROCESS OFF)
   set_property(SOURCE no_preprocess_source_upper.F no_preprocess_source_fpp.fpp PROPERTY Fortran_PREPROCESS OFF)
 endif()
+
+# Issue 25112
+set(CMAKE_Fortran_MODULE_DIRECTORY "${PROJECT_BINARY_DIR}/include")
+add_library(objmod OBJECT objmod.f90)
+add_executable(objmain objmain.f90)
+target_link_libraries(objmain PRIVATE objmod)

Tests/FortranOnly/objmain.f90

@@ -0,0 +1,5 @@
+program main
+    use objmod, only : hello
+    implicit none
+    call hello()
+end program

Tests/FortranOnly/objmod.f90

@@ -0,0 +1,7 @@
+module objmod
+    implicit none
+contains
+    subroutine hello()
+        print '(a)', "hello world"
+    end subroutine hello
+end module objmod