Find{BLAS,LAPACK}: Search always in dynamic linker paths

Previously the search in the dynamic linker paths 'LIB', 'LD_LIBRARY_PATH'
and 'DYLD_LIBRARY_PATH' was dependent on the value of the environment
variable 'MKLROOT'. If MKLROOT was given, the dynamic linker paths where
not searched. This seems slightly counter-intuitive.
This PR changes the behavior so that MKLROOT is searched first, but if
unsuccesful, the dynamic linker paths are tried as well.

Modules/FindBLAS.cmake

@@ -161,14 +161,12 @@ macro(CHECK_BLAS_LIBRARIES LIBRARIES _prefix _name _flags _list _threadlibs _add
   set(${LIBRARIES})
   set(_combined_name)
 
-  if(NOT _addlibdir)
-    if(WIN32)
-      set(_addlibdir ENV LIB)
-    elseif(APPLE)
-      set(_addlibdir ENV DYLD_LIBRARY_PATH)
-    else()
-      set(_addlibdir ENV LD_LIBRARY_PATH)
-    endif()
+  if(WIN32)
+    list(APPEND _addlibdir ENV LIB)
+  elseif(APPLE)
+    list(APPEND _addlibdir ENV DYLD_LIBRARY_PATH)
+  else()
+    list(APPEND _addlibdir ENV LD_LIBRARY_PATH)
   endif()
   list(APPEND _addlibdir "${CMAKE_C_IMPLICIT_LINK_DIRECTORIES}")
 

Modules/FindLAPACK.cmake

@@ -131,14 +131,12 @@ macro(CHECK_LAPACK_LIBRARIES LIBRARIES _prefix _name _flags _list _threadlibs _a
   set(${LIBRARIES})
   set(_combined_name)
 
-  if(NOT _addlibdir)
-    if(WIN32)
-      set(_addlibdir ENV LIB)
-    elseif(APPLE)
-      set(_addlibdir ENV DYLD_LIBRARY_PATH)
-    else()
-      set(_addlibdir ENV LD_LIBRARY_PATH)
-    endif()
+  if(WIN32)
+    list(APPEND _addlibdir ENV LIB)
+  elseif(APPLE)
+    list(APPEND _addlibdir ENV DYLD_LIBRARY_PATH)
+  else()
+    list(APPEND _addlibdir ENV LD_LIBRARY_PATH)
   endif()
   list(APPEND _addlibdir "${CMAKE_C_IMPLICIT_LINK_DIRECTORIES}")