Library restructure (#104)

* Move wasmer-runtime to wasmer-runtime-core

* Add the runtime library

* Fix issue with macros using wasmer_runtime, fmt

* Make default compiler dependency optional

* Add instantiate and validate functions

lib/runtime-core/examples/test.rs

@@ -0,0 +1,55 @@
+use wabt::wat2wasm;
+use wasmer_clif_backend::CraneliftCompiler;
+use wasmer_runtime_core::{import::ImportObject, Instance};
+
+fn main() {
+    let mut instance = create_module_1();
+    let result = instance.call("call-overwritten-element", &[]);
+    println!("result: {:?}", result);
+}
+
+fn create_module_1() -> Instance {
+    let module_str = r#"(module
+      (type (;0;) (func (result i32)))
+      (import "spectest" "table" (table (;0;) 10 anyfunc))
+      (func (;0;) (type 0) (result i32)
+        i32.const 65)
+      (func (;1;) (type 0) (result i32)
+        i32.const 66)
+      (func (;2;) (type 0) (result i32)
+        i32.const 9
+        call_indirect (type 0))
+      (export "call-overwritten-element" (func 2))
+      (elem (;0;) (i32.const 9) 0)
+      (elem (;1;) (i32.const 9) 1))
+    "#;
+    let wasm_binary = wat2wasm(module_str.as_bytes()).expect("WAST not valid or malformed");
+    let module = wasmer_runtime_core::compile_with(&wasm_binary[..], &CraneliftCompiler::new())
+        .expect("WASM can't be compiled");
+    module
+        .instantiate(generate_imports())
+        .expect("WASM can't be instantiated")
+}
+
+static IMPORT_MODULE: &str = r#"
+(module
+  (type $t0 (func (param i32)))
+  (type $t1 (func))
+  (func $print_i32 (export "print_i32") (type $t0) (param $lhs i32))
+  (func $print (export "print") (type $t1))
+  (table $table (export "table") 10 20 anyfunc)
+  (memory $memory (export "memory") 1 2)
+  (global $global_i32 (export "global_i32") i32 (i32.const 666)))
+"#;
+
+pub fn generate_imports() -> ImportObject {
+    let wasm_binary = wat2wasm(IMPORT_MODULE.as_bytes()).expect("WAST not valid or malformed");
+    let module = wasmer_runtime_core::compile_with(&wasm_binary[..], &CraneliftCompiler::new())
+        .expect("WASM can't be compiled");
+    let instance = module
+        .instantiate(ImportObject::new())
+        .expect("WASM can't be instantiated");
+    let mut imports = ImportObject::new();
+    imports.register("spectest", instance);
+    imports
+}