Merge topic 'clang-PIE'

ada9efd Clang: All versions know about -fPIE (#13550)
6e34aea Clang: Split Compiler/Clang* modules out from GNU (#13550)

Modules/Compiler/Clang-ASM.cmake

@@ -1 +1,5 @@
-include(Compiler/GNU-ASM)
+include(Compiler/Clang)
+
+set(CMAKE_ASM_SOURCE_FILE_EXTENSIONS s;S;asm)
+
+__compiler_clang(ASM)

Modules/Compiler/Clang-C.cmake

@@ -1 +1,2 @@
-include(Compiler/GNU-C)
+include(Compiler/Clang)
+__compiler_clang(C)

Modules/Compiler/Clang-CXX.cmake

@@ -1 +1,2 @@
-include(Compiler/GNU-CXX)
+include(Compiler/Clang)
+__compiler_clang(CXX)

Modules/Compiler/Clang.cmake

@@ -0,0 +1,26 @@
+
+#=============================================================================
+# Copyright 2002-2012 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+# This module is shared by multiple languages; use include blocker.
+if(__COMPILER_CLANG)
+  return()
+endif()
+set(__COMPILER_CLANG 1)
+
+include(Compiler/GNU)
+
+macro(__compiler_clang lang)
+  __compiler_gnu(${lang})
+  set(CMAKE_${lang}_COMPILE_OPTIONS_PIE "-fPIE")
+endmacro()