ENH: add LDFLAGS as an initial value for all linker flags, good for -64

Modules/CMakeSystemSpecificInformation.cmake

@@ -158,7 +158,7 @@ SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS_ENV_INIT} $ENV{CXXFLAGS} ${CMAKE_CXX_FLA
 SET (CMAKE_C_FLAGS "${CMAKE_C_FLAGS_ENV_INIT} $ENV{CFLAGS} ${CMAKE_C_FLAGS_INIT}" CACHE STRING
      "Flags for C compiler.")
 
-SET (CMAKE_EXE_LINKER_FLAGS ${CMAKE_EXE_LINKER_FLAGS_INIT}
+SET (CMAKE_EXE_LINKER_FLAGS ${CMAKE_EXE_LINKER_FLAGS_INIT} $ENV{LDFLAGS}
      CACHE STRING "Flags used by the linker.")
 
 IF(NOT CMAKE_NOT_USING_CONFIG_FLAGS)
@@ -230,11 +230,11 @@ ENDIF(NOT CMAKE_NOT_USING_CONFIG_FLAGS)
 
 
 # shared linker flags
-SET (CMAKE_SHARED_LINKER_FLAGS ${CMAKE_SHARED_LINKER_FLAGS_INIT}
+SET (CMAKE_SHARED_LINKER_FLAGS ${CMAKE_SHARED_LINKER_FLAGS_INIT} $ENV{LDFLAGS}
      CACHE STRING "Flags used by the linker during the creation of dll's.")
 
 # module linker flags
-SET (CMAKE_MODULE_LINKER_FLAGS ${CMAKE_MODULE_LINKER_FLAGS_INIT}
+SET (CMAKE_MODULE_LINKER_FLAGS ${CMAKE_MODULE_LINKER_FLAGS_INIT} $ENV{LDFLAGS}
      CACHE STRING "Flags used by the linker during the creation of modules.")
 
 SET(CMAKE_BUILD_TOOL ${CMAKE_MAKE_PROGRAM} CACHE INTERNAL