Don't add -std flag to CMAKE_CXX_FLAGS

Use the cmake method, and consolidate setting the language standard in
one place.

Change-Id: I96826c31955b1553ed1beb94203c99933075bb0a


[ROCm/clr commit: dd5f255c7e]

projects/clr/opencl/CMakeLists.txt

@@ -7,6 +7,10 @@ endif()
 
 project(opencl)
 
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
 #example command:
 # cmake -DCMAKE_PREFIX_PATH=/path/to/ROCclr/build/or/install ..
 

projects/clr/opencl/amdocl/CMakeLists.txt

@@ -1,7 +1,4 @@
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 # Some linker flags, -Wl,--unresolved-symbols=report-all being one of them, requires -shared-libasan if using -fsanitize=address.

projects/clr/opencl/tools/clinfo/CMakeLists.txt

@@ -1,7 +1,3 @@
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-set(CMAKE_CXX_EXTENSIONS OFF)
-
 
 set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 

projects/clr/opencl/tools/cltrace/CMakeLists.txt

@@ -1,5 +1,3 @@
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-
 if(CMAKE_BUILD_TYPE MATCHES "^Debug$")
   add_definitions(-DDEBUG)
 endif()