[CMake] Move project() call to main CMake file

Summary:
The main CMake file don't have a project() call. In this case, cmake will run a dummy project(Project ) at the very beginning. Even before cmake_minimum_required. And a series of compiler detections will be triggered.

This is problematic if we depends on some policy to be set. E.g. CMP0056. try_compile will fail before we have a chance to do anything.

Subscribers: mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D65362

llvm-svn: 367273

lldb/CMakeLists.txt

@@ -14,6 +14,7 @@ set(CMAKE_MODULE_PATH
 # If we are not building as part of LLVM, build LLDB as a standalone project,
 # using LLVM as an external library.
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  project(lldb)
   include(LLDBStandalone)
 endif()
 

lldb/cmake/modules/LLDBStandalone.cmake

@@ -1,5 +1,3 @@
-project(lldb)
-
 option(LLVM_INSTALL_TOOLCHAIN_ONLY "Only include toolchain files in the 'install' target." OFF)
 
 find_package(LLVM REQUIRED CONFIG HINTS "${LLVM_DIR}" NO_CMAKE_FIND_ROOT_PATH)