Tests: Fix FortranOnly test with Intel compiler on Windows

The test regularly fails updating the `vc*.pdb` compiler-generated
PDB file.  Add the `/Z7` flag as the compiler suggests for this.

Tests/FortranOnly/CMakeLists.txt

@@ -2,6 +2,11 @@ cmake_minimum_required(VERSION 2.8.12)
 project(FortranOnly Fortran)
 message("CTEST_FULL_OUTPUT ")
 
+if("${CMAKE_Fortran_COMPILER_ID};${CMAKE_Fortran_SIMULATE_ID}" MATCHES "^Intel(LLVM)?;MSVC$")
+  string(APPEND CMAKE_Fortran_FLAGS_DEBUG " -Z7")
+  string(APPEND CMAKE_Fortran_FLAGS_RELWITHDEBINFO " -Z7")
+endif()
+
 # create a library with hello and world functions
 add_library(FortranOnlylib hello.f world.f)
 set_property(TARGET FortranOnlylib PROPERTY Fortran_FORMAT FIXED)