Fix Building Support Library with NDK r25

* Add flags -Wno-c99-designator and -Wno-unused-but-set-variable


Signed-off-by: Kevin May <kevin.may@arm.com>
Change-Id: I7b1a1a353a0474d7ef967f6f3c8d13c36fa31844
diff --git a/shim/sl/CMakeLists.txt b/shim/sl/CMakeLists.txt
index 0ba6390..6912640 100644
--- a/shim/sl/CMakeLists.txt
+++ b/shim/sl/CMakeLists.txt
@@ -57,6 +57,7 @@
 add_library(base STATIC ${base_sources})
 target_include_directories (base PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_include_directories (base PUBLIC ${libnnapi_support_include_directories})
+target_compile_options(base PUBLIC -Wno-c99-designator)
 
 file(GLOB TYPES_CL_SOURCE_FILES
     ${AOSP_MODULES_ROOT}/packages/modules/NeuralNetworks/common/operations/*Validation.cpp
@@ -141,6 +142,7 @@
 add_library(neuralnetworks_common_cl STATIC ${neuralnetworks_common_cl_sources})
 target_include_directories (neuralnetworks_common_cl PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_include_directories (neuralnetworks_common_cl PUBLIC ${libnnapi_support_include_directories})
+target_compile_options(neuralnetworks_common_cl PUBLIC -Wno-unused-but-set-variable)
 
 set(neuralnetworks_cl_sources)
 list(APPEND neuralnetworks_cl_sources