cmake: fix UNICODE-escaped characters on aarch64

Signed-off-by: Rama Malladi <[email protected]>

CMakeLists.txt

@@ -107,6 +107,9 @@ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/library")
 option(FLB_ALL                 "Enable all features"                         No)
 option(FLB_DEBUG               "Build with debug mode (-g)"                 Yes)
 option(FLB_RELEASE             "Build with release mode (-O2 -g -DNDEBUG)"   No)
+if (CMAKE_SYSTEM_PROCESSOR MATCHES "^(arm64|aarch64)")
+  set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsigned-char")
+endif()
 set(FLB_IPO "ReleaseOnly" CACHE STRING "Build with interprocedural optimization")
 set_property(CACHE FLB_IPO PROPERTY STRINGS "On;Off;ReleaseOnly")
 option(FLB_SMALL               "Optimise for small size"       No)