Use less c++

As a design, it would be better if we didn't need to have a dependency
on c++ in a c library.  Moving things to C will reduce both
dependencies and compile times.

Reduced dependencies makes the library itself easier to use in
more environments.

libmctp Is a library that doesn't take a dependency on gtest for its
tests
libpldm Is an example that does take a dependency on gtest.

Change-Id: If1dc638f87b75b28181a0baf67f5a18d389cff81
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/meson.build b/meson.build
index e669bb8..96e194c 100644
--- a/meson.build
+++ b/meson.build
@@ -21,6 +21,8 @@
 add_project_arguments('-DLIBCPER_EXAMPLES="'
     + meson.current_source_dir() + '/examples"', language: ['c', 'cpp'])
 
+add_project_arguments('-Wno-unused-function', language: ['c', 'cpp'])
+
 library_is_share = get_option('default_library') == 'shared'
 add_project_arguments('-D_POSIX_C_SOURCE=200809L', language: 'c')
 
@@ -74,11 +76,9 @@
 cc = meson.get_compiler('c')
 
 json_c_dep = dependency('json-c')
-
 libcper_include = ['include']
 libcper_include_dir = include_directories(libcper_include, is_system: true)
 
-
 libcper_parse_sources += files(
     'base64.c',
     'common-utils.c',