Skipping PCH unit test for lcc compiler

test cases/common/13 pch/meson.build

@@ -1,4 +1,10 @@
 project('pch test', 'c')
 
+cc = meson.get_compiler('c')
+cc_id = cc.get_id()
+if cc_id == 'lcc'
+  error('MESON_SKIP_TEST: Elbrus compiler does not support PCH.')
+endif
+
 exe = executable('prog', 'prog.c',
 c_pch : ['pch/prog_pch.c', 'pch/prog.h'])