Directly link libcapstone for easier development

This lets us use libcapstone directly from miniruby so we don't need a
Ruby Gem to to dev work.

Example usage:

```ruby
def foo(x)
  if x < 1
    "wow"
  else
    "neat"
  end
end

iseq = RubyVM::InstructionSequence.of(method(:foo))
puts UJIT.disasm(iseq)
100.times { foo 1 }
puts UJIT.disasm(iseq)
```

Then in the terminal

```
$ ./miniruby test.rb

== disasm: #<ISeq:foo@test.rb:1 (1,0)-(7,3)> (catch: FALSE)
local table (size: 1, argc: 1 [opts: 0, rest: -1, post: 0, block: -1, kw: -1@-1, kwrest: -1])
[ 1] x@0<Arg>
0000 getlocal_WC_0                          x@0                       (   2)[LiCa]
0002 putobject_INT2FIX_1_
0003 opt_lt                                 <calldata!mid:<, argc:1, ARGS_SIMPLE>
0005 branchunless                           10
0007 putstring                              "wow"                     (   3)[Li]
0009 leave                                                            (   7)[Re]
0010 putstring                              "neat"                    (   5)[Li]
0012 leave                                                            (   7)[Re]

== ISEQ RANGE: 10 -> 10 ========================================================
        0x0:    movabs  rax, 0x7fe816e2d1a0
        0xa:    mov     qword ptr [rdi], rax
        0xd:    mov     r8, rax
        0x10:   mov     r9, rax
        0x13:   mov     r11, r12
        0x16:   jmp     qword ptr [rax]
== ISEQ RANGE: 0 -> 7 ==========================================================
        0x0:    mov     rax, qword ptr [rdi + 0x20]
        0x4:    mov     rax, qword ptr [rax - 0x18]
        0x8:    mov     qword ptr [rdx], rax
        0xb:    mov     qword ptr [rdx + 8], 3
        0x13:   movabs  rax, 0x7fe817808200
        0x1d:   test    byte ptr [rax + 0x3e6], 1
        0x24:   jne     0x3ffff7b
        0x2a:   test    byte ptr [rdx], 1
        0x2d:   je      0x3ffff7b
        0x33:   test    byte ptr [rdx + 8], 1
        0x37:   je      0x3ffff7b
        0x3d:   mov     rax, qword ptr [rdx]
        0x40:   cmp     rax, qword ptr [rdx + 8]
        0x44:   movabs  rax, 0
        0x4e:   movabs  rcx, 0x14
        0x58:   cmovl   rax, rcx
        0x5c:   mov     qword ptr [rdx], rax
        0x5f:   test    qword ptr [rdx], -9
        0x66:   jne     0x3ffffd5
```

Make sure to `brew install pkg-config capstone`

1 files changed, 1 insertions, 0 deletions

diff --git a/inits.c b/inits.c
index f69ee73a89..059055246a 100644
--- a/inits.c
+++ b/inits.c
@@ -99,6 +99,7 @@ rb_call_builtin_inits(void)
     BUILTIN(timev);
     BUILTIN(nilclass);
     BUILTIN(marshal);
+    BUILTIN(ujit);
     Init_builtin_prelude();
 }
 #undef CALL