Modules: Restore recently removed search path suffixes

Refactoring in commit v3.11.0-rc1~293^2~4 (Modules: Remove paths set as
global Unix prefixes, 2017-11-20) removed `PATH_SUFFIXES` options that
appeared to be used to cover subdirectories of the `PATHS` options that
were also removed.  However, the path suffixes also apply to other
search paths and so should not be removed.  Restore them.

Fixes: #17760

Modules/FindGDAL.cmake

@@ -49,6 +49,7 @@ find_path(GDAL_INCLUDE_DIR gdal.h
   PATH_SUFFIXES
      include/gdal
      include/GDAL
+     include
 )
 
 if(UNIX)
@@ -60,6 +61,7 @@ if(UNIX)
         HINTS
           ENV GDAL_DIR
           ENV GDAL_ROOT
+        PATH_SUFFIXES bin
     )
 
     if(GDAL_CONFIG)
@@ -79,6 +81,7 @@ find_library(GDAL_LIBRARY
      ENV GDAL_DIR
      ENV GDAL_ROOT
      ${_gdal_libpath}
+  PATH_SUFFIXES lib
 )
 
 include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)

Modules/FindGIF.cmake

@@ -30,6 +30,7 @@
 find_path(GIF_INCLUDE_DIR gif_lib.h
   HINTS
     ENV GIF_DIR
+  PATH_SUFFIXES include
 )
 
 # the gif library can have many names :-/
@@ -39,6 +40,7 @@ find_library(GIF_LIBRARY
   NAMES ${POTENTIAL_GIF_LIBS}
   HINTS
     ENV GIF_DIR
+  PATH_SUFFIXES lib
 )
 
 # see readme.txt

Modules/FindOpenThreads.cmake

@@ -58,6 +58,7 @@ find_path(OPENTHREADS_INCLUDE_DIR OpenThreads/Thread
         ENV OSG_ROOT
         ${OPENTHREADS_DIR}
         ${OSG_DIR}
+    PATH_SUFFIXES include
 )
 
 
@@ -73,6 +74,7 @@ find_library(OPENTHREADS_LIBRARY
         ENV OSG_ROOT
         ${OPENTHREADS_DIR}
         ${OSG_DIR}
+    PATH_SUFFIXES lib
 )
 
 find_library(OPENTHREADS_LIBRARY_DEBUG
@@ -88,6 +90,7 @@ find_library(OPENTHREADS_LIBRARY_DEBUG
         ENV OSG_ROOT
         ${OPENTHREADS_DIR}
         ${OSG_DIR}
+    PATH_SUFFIXES lib
 )
 
 if(OPENTHREADS_LIBRARY_DEBUG)

Modules/Findosg_functions.cmake

@@ -28,6 +28,7 @@ function(OSG_FIND_PATH module header)
             ENV OSG_ROOT
             ${${module_uc}_DIR}
             ${OSG_DIR}
+       PATH_SUFFIXES include
    )
 endfunction()
 
@@ -47,6 +48,7 @@ function(OSG_FIND_LIBRARY module library)
             ENV OSG_ROOT
             ${${module_uc}_DIR}
             ${OSG_DIR}
+       PATH_SUFFIXES lib
    )
 
    find_library(${module_uc}_LIBRARY_DEBUG
@@ -58,6 +60,7 @@ function(OSG_FIND_LIBRARY module library)
             ENV OSG_ROOT
             ${${module_uc}_DIR}
             ${OSG_DIR}
+       PATH_SUFFIXES lib
     )
 
    if(NOT ${module_uc}_LIBRARY_DEBUG)