Call cmake_minimum_required at the top of CMakeLists.txt

[pirama]

Summary

Since r298413, the NEW behavior of the CMake policy CMP0056 is followed.
However, it is only effective after the call to cmake_minimum_required.
This causes CMAKE_EXE_LINKER_FLAGS etc. to be unused when CMake tries to
check compilers for languages specified in the 'project' declaration.

Set cmake_minimum_required(VERSION) at the top of the file and ahead of
declaring the project declaration.

[pirama]

Update commit message.

[beanz]

LGTM

[pirama]

Thanks for the LGTM!

CMakeLists.txt

 # CMake build for CompilerRT.
 #
 # This build assumes that CompilerRT is checked out into the
 # 'projects/compiler-rt' or 'runtimes/compiler-rt' inside of an LLVM tree.
 # Standalone build system for CompilerRT is not yet ready.
 #
 # An important constraint of the build is that it only produces libraries
 # based on the ability of the host toolchain to target various platforms.
 
+cmake_minimum_required(VERSION 3.4.3)
+
 # Check if compiler-rt is built as a standalone project.
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR COMPILER_RT_STANDALONE_BUILD)
   project(CompilerRT C CXX ASM)
   set(COMPILER_RT_STANDALONE_BUILD TRUE)
 endif()
 
-cmake_minimum_required(VERSION 3.4.3)
-
 # Add path for custom compiler-rt modules.
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
   )
 
 include(base-config-ix)
 include(CompilerRTUtils)