Some automated bindgen tests fail

[tmfink]

This happens because of rust-lang/rust-bindgen#1213

Possible solutions:

• Disable tests
• Conditionally disable tests on archs that fail them
• Refactor tests into a separate file

Example on stable-i686-pc-windows-msvc:

$ cargo test
    Finished dev [unoptimized + debuginfo] target(s) in 0.0 secs
     Running target\debug\deps\capstone_sys-4b9bbef9612e834d.exe

running 53 tests
test bindgen_test_layout___va_list_tag ... FAILED
test bindgen_test_layout_arm64_op_mem ... ok
test bindgen_test_layout_arm_op_mem ... ok
test bindgen_test_layout_cs_arm ... ok
test bindgen_test_layout_cs_arm64 ... ok
test bindgen_test_layout_cs_arm64_op ... ok
test bindgen_test_layout_cs_arm64_op__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_arm64_op__bindgen_ty_2 ... ok
test bindgen_test_layout_cs_arm_op ... ok
test bindgen_test_layout_cs_arm_op__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_arm_op__bindgen_ty_2 ... ok
test bindgen_test_layout_cs_detail ... ok
test bindgen_test_layout_cs_detail__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_insn ... FAILED
test bindgen_test_layout_cs_mips ... ok
test bindgen_test_layout_cs_mips_op ... ok
test bindgen_test_layout_cs_mips_op__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_opt_mem ... FAILED
test bindgen_test_layout_cs_opt_skipdata ... FAILED
test bindgen_test_layout_cs_ppc ... ok
test bindgen_test_layout_cs_ppc_op ... ok
test bindgen_test_layout_cs_ppc_op__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_sparc ... ok
test bindgen_test_layout_cs_sparc_op ... ok
test bindgen_test_layout_cs_sparc_op__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_sysz ... ok
test bindgen_test_layout_cs_sysz_op ... ok
test bindgen_test_layout_cs_sysz_op__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_x86 ... ok
test bindgen_test_layout_cs_x86_op ... ok
test bindgen_test_layout_cs_x86_op__bindgen_ty_1 ... ok
test bindgen_test_layout_cs_xcore ... ok
test bindgen_test_layout_cs_xcore_op ... ok
test bindgen_test_layout_cs_xcore_op__bindgen_ty_1 ... ok
test bindgen_test_layout_mips_op_mem ... ok
test bindgen_test_layout_ppc_op_crx ... ok
test bindgen_test_layout_ppc_op_mem ... ok
test bindgen_test_layout_sparc_op_mem ... ok
test bindgen_test_layout_sysz_op_mem ... ok
test bindgen_test_layout_x86_op_mem ... ok
test bindgen_test_layout_xcore_op_mem ... ok
test test::test_arch_arm ... ok
test test::test_arch_arm64 ... ok
test test::test_arch_mips ... ok
test test::test_arch_ppc ... ok
test test::test_arch_sparc ... ok
test test::test_arch_sysz ... ok
test test::test_arch_x86 ... ok
test test::test_arch_xcore ... ok
test test::test_cs_support ... ok
test test::test_cs_version ... ok
test test::test_non_arch_types ... ok
test test::test_x86_disassembly ... ok

failures:

---- bindgen_test_layout___va_list_tag stdout ----
	thread 'bindgen_test_layout___va_list_tag' panicked at 'assertion failed: `(left == right)`
  left: `16`,
 right: `24`: Size of: __va_list_tag', target\debug\build\capstone-sys-346b4f8e4123ac85\out/capstone.rs:9016:4
note: Run with `RUST_BACKTRACE=1` for a backtrace.

---- bindgen_test_layout_cs_insn stdout ----
	thread 'bindgen_test_layout_cs_insn' panicked at 'assertion failed: `(left == right)`
  left: `232`,
 right: `240`: Size of: cs_insn', target\debug\build\capstone-sys-346b4f8e4123ac85\out/capstone.rs:8602:4

---- bindgen_test_layout_cs_opt_mem stdout ----
	thread 'bindgen_test_layout_cs_opt_mem' panicked at 'assertion failed: `(left == right)`
  left: `20`,
 right: `40`: Size of: cs_opt_mem', target\debug\build\capstone-sys-346b4f8e4123ac85\out/capstone.rs:100:4

---- bindgen_test_layout_cs_opt_skipdata stdout ----
	thread 'bindgen_test_layout_cs_opt_skipdata' panicked at 'assertion failed: `(left == right)`
  left: `12`,
 right: `24`: Size of: cs_opt_skipdata', target\debug\build\capstone-sys-346b4f8e4123ac85\out/capstone.rs:189:4


failures:
    bindgen_test_layout___va_list_tag
    bindgen_test_layout_cs_insn
    bindgen_test_layout_cs_opt_mem
    bindgen_test_layout_cs_opt_skipdata

test result: FAILED. 49 passed; 4 failed; 0 ignored; 0 measured; 0 filtered out

error: test failed, to rerun pass '--lib'

This was reported by @mthiesen in #17

[tmfink]

Fixed with #25