Update CMake developer warnings for GCC < 7

 - Ensure that there aren't build failures when OPENCOARRAYS_DEVELOPER=ON

Author: zbeekman

CMakeLists.txt

@@ -555,7 +555,7 @@ if(opencoarrays_aware_compiler)
     message( STATUS "Allocatable components of coarray derived types only supported in GFortran >= 7 with OpenCoarrays > 1.8.4" )
     message( STATUS "(but full support not anticipated until OpenCoarrays 2.0 release)" )
     if (CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 7.0.0)
-      message( WARNING "Allocatable components of coarray derived type developer tests enabled, despite lack of support in GFortran < 7\n These tests should fail." )
+      message( AUTHOR_WARNING "Allocatable components of coarray derived type developer tests enabled, despite lack of support in GFortran < 7\n These tests should fail." )
     endif()
     add_caf_test(register_alloc_comp_1 2 register_alloc_comp_1)
     add_caf_test(register_alloc_comp_2 2 register_alloc_comp_2)
@@ -599,7 +599,7 @@ if(opencoarrays_aware_compiler)
   # Regression tests based on reported issues
   if((gfortran_compiler AND (NOT CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 7.0.0)) OR (CAF_RUN_DEVELOPER_TESTS OR $ENV{OPENCOARRAYS_DEVELOPER}))
     if( CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 7.0.0 )
-      message( WARNING "Developer tests requested and GFortran < 7: test source-alloc-no-sync may fail" )
+      message( AUTHOR_WARNING "Developer tests requested and GFortran < 7: test source-alloc-no-sync may fail" )
     endif()
     # GFortran PR 78505 only fixed on trunk/gcc 7, issue #243
     add_caf_test(source-alloc-no-sync 8 source-alloc-sync)

src/tests/unit/init_register/CMakeLists.txt

@@ -5,12 +5,21 @@ caf_compile_executable(register_alloc_vector register_alloc_vector.f90)
 caf_compile_executable(allocate_as_barrier allocate_as_barrier.f90)
 caf_compile_executable(allocate_as_barrier_proc allocate_as_barrier_proc.f90)
 
-if (gfortran_compiler AND (NOT CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 7.0.0) OR (CAF_RUN_DEVELOPER_TESTS OR $ENV{OPENCOARRAYS_DEVELOPER}))
+if (gfortran_compiler AND (NOT CMAKE_Fortran_COMPILER_VERSION VERSION_LESS 7.0.0))
   caf_compile_executable(async_comp_alloc async_comp_alloc.f90)
   caf_compile_executable(async_comp_alloc_2 async_comp_alloc_2.f90)
   caf_compile_executable(register_alloc_comp_1 register_alloc_comp_1.f90)
   caf_compile_executable(register_alloc_comp_2 register_alloc_comp_2.f90)
   caf_compile_executable(register_alloc_comp_3 register_alloc_comp_3.f90)
   caf_compile_executable(comp_allocated_1 comp_allocated_1.f90)
   caf_compile_executable(comp_allocated_2 comp_allocated_2.f90)
+elseif((CAF_RUN_DEVELOPER_TESTS OR $ENV{OPENCOARRAYS_DEVELOPER}))
+  message( AUTHOR_WARNING "Skipping building the following tests due to GFortran < 7.x lack of compatibility:
+    async_comp_alloc.f90
+    async_comp_alloc_2.f90
+    register_alloc_comp_1.f90
+    register_alloc_comp_2.f90
+    register_alloc_comp_3.f90
+    comp_allocated_1.f90
+    comp_allocated_2.f90" )
 endif()