Fixed precompiled headers support detection

cmake/OpenCVPCHSupport.cmake

-# taken from http://www.vtk.org/Bug/view.php?id=1260 and slightly adjusted
+# taken from http://public.kitware.com/Bug/view.php?id=1260 and slightly adjusted
 
 # - Try to find precompiled headers support for GCC 3.4 and 4.x
 # Once done this will define:
@@ -26,8 +26,8 @@ IF(CMAKE_COMPILER_IS_GNUCXX)
     SET(_PCH_include_prefix "-I")
     SET(_PCH_isystem_prefix "-isystem")
 
-ELSEIF(WIN32)
-    SET(PCHSupport_FOUND TRUE) # for experimental msvc support
+ELSEIF(CMAKE_GENERATOR MATCHES "^Visual.*$")
+    SET(PCHSupport_FOUND TRUE)
     SET(_PCH_include_prefix "/I")
     SET(_PCH_isystem_prefix "/I")
 ELSE()
@@ -324,3 +324,17 @@ MACRO(ADD_NATIVE_PRECOMPILED_HEADER _targetName _input)
     endif()
 
 ENDMACRO(ADD_NATIVE_PRECOMPILED_HEADER)
+
+macro(ocv_add_precompiled_header_to_target the_target pch_header)
+  if(PCHSupport_FOUND AND ENABLE_PRECOMPILED_HEADERS AND EXISTS "${pch_header}")
+    if(CMAKE_GENERATOR MATCHES Visual)
+      set(${the_target}_pch "${pch_header}")
+      add_native_precompiled_header(${the_target} ${pch_header})
+      unset(${the_target}_pch)
+    elseif(CMAKE_GENERATOR MATCHES Xcode)
+      add_native_precompiled_header(${the_target} ${pch_header})
+    elseif(CMAKE_COMPILER_IS_GNUCXX AND CMAKE_GENERATOR MATCHES "Makefiles|Ninja")
+      add_precompiled_header(${the_target} ${pch_header})
+    endif()
+  endif()
+endmacro()

cmake/OpenCVUtils.cmake

@@ -384,6 +384,17 @@ macro(ocv_list_add_suffix LST SUFFIX)
 endmacro()
 
 
+# gets and removes the first element from list
+macro(ocv_list_pop_front LST VAR)
+  if(${LST})
+    list(GET ${LST} 0 ${VAR})
+    list(REMOVE_AT ${LST} 0)
+  else()
+    set(${VAR} "")
+  endif()
+endmacro()
+
+
 # simple regex escaping routine (does not cover all cases!!!)
 macro(ocv_regex_escape var regex)
   string(REGEX REPLACE "([+.*^$])" "\\\\1" ${var} "${regex}")
@@ -401,7 +412,7 @@ endmacro()
 
 
 # convert list of paths to full paths
-macro(ocv_to_full_paths VAR)
+macro(ocv_convert_to_full_paths VAR)
   if(${VAR})
     set(__tmp "")
     foreach(path ${${VAR}})