Set proper sharedLibraryName for MinGW in installed assimpTargets-*.cmake

The shared library name for MinGW is the .a library with which we need to
link the built binary. This problem is described in issue #2685.

assimpTargets-debug.cmake.in

@@ -63,7 +63,12 @@ if(MSVC)
 else()
   set(ASSIMP_LIBRARY_SUFFIX "@ASSIMP_LIBRARY_SUFFIX@" CACHE STRING "the suffix for the assimp libraries" )
   if(ASSIMP_BUILD_SHARED_LIBS)
-    set(sharedLibraryName "libassimp${ASSIMP_LIBRARY_SUFFIX}@CMAKE_DEBUG_POSTFIX@@CMAKE_SHARED_LIBRARY_SUFFIX@.@ASSIMP_VERSION_MAJOR@")
+    if(WIN32)
+      # Handle MinGW compiler.
+      set(sharedLibraryName "libassimp${ASSIMP_LIBRARY_SUFFIX}@CMAKE_DEBUG_POSTFIX@@CMAKE_SHARED_LIBRARY_SUFFIX@@CMAKE_STATIC_LIBRARY_SUFFIX@")
+    else()
+      set(sharedLibraryName "libassimp${ASSIMP_LIBRARY_SUFFIX}@CMAKE_DEBUG_POSTFIX@@CMAKE_SHARED_LIBRARY_SUFFIX@.@ASSIMP_VERSION_MAJOR@")
+    endif()
     set_target_properties(assimp::assimp PROPERTIES
       IMPORTED_SONAME_DEBUG "${sharedLibraryName}"
       IMPORTED_LOCATION_DEBUG "${_IMPORT_PREFIX}/lib/${sharedLibraryName}"

assimpTargets-release.cmake.in

@@ -63,7 +63,12 @@ if(MSVC)
 else()
   set(ASSIMP_LIBRARY_SUFFIX "@ASSIMP_LIBRARY_SUFFIX@" CACHE STRING "the suffix for the assimp libraries" )
   if(ASSIMP_BUILD_SHARED_LIBS)
-    set(sharedLibraryName "libassimp${ASSIMP_LIBRARY_SUFFIX}@CMAKE_SHARED_LIBRARY_SUFFIX@.@ASSIMP_VERSION_MAJOR@")
+    if(WIN32)
+      # Handle MinGW compiler.
+      set(sharedLibraryName "libassimp${ASSIMP_LIBRARY_SUFFIX}@CMAKE_DEBUG_POSTFIX@@CMAKE_SHARED_LIBRARY_SUFFIX@@CMAKE_STATIC_LIBRARY_SUFFIX@")
+    else()
+      set(sharedLibraryName "libassimp${ASSIMP_LIBRARY_SUFFIX}@CMAKE_DEBUG_POSTFIX@@CMAKE_SHARED_LIBRARY_SUFFIX@.@ASSIMP_VERSION_MAJOR@")
+    endif()
     set_target_properties(assimp::assimp PROPERTIES
       IMPORTED_SONAME_RELEASE "${sharedLibraryName}"
       IMPORTED_LOCATION_RELEASE "${_IMPORT_PREFIX}/lib/${sharedLibraryName}"