Initial reorg.

This is largely the same as #305, but updated for the current tree.

crates/misc/py/examples/two_modules/.gitignore

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+one.wasm
+two.wasm
+__pycache__

crates/misc/py/examples/two_modules/README.md

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+# Build example's file
+
+To build `one.wasm` use rustc (nightly) for wasm32 target with debug information:
+
+```
+rustc +nightly --target=wasm32-unknown-unknown one.rs --crate-type=cdylib
+```
+
+To build `two.wasm` use wabt.
+```
+wat2wasm two.wat -o two.wasm
+```
+
+# Run example
+
+Point path to the built wasmtime_py library location when running python, e.g.
+
+```
+PYTHONPATH=../../target/debug python3 run.py
+```

crates/misc/py/examples/two_modules/env.py

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+def answer() -> 'i32':
+    return 42

crates/misc/py/examples/two_modules/one.rs

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+
+extern "C" {
+    fn answer() -> u32;
+}
+
+// For the purpose of this wasm example, we don't worry about multi-threading,
+// and will be using the PLACE in unsafe manner below.
+static mut PLACE: u32 = 23;
+
+#[no_mangle]
+pub extern fn bar() -> *const u32 {
+    unsafe { 
+        PLACE = answer();
+        // Return a pointer to the exported memory.
+        (&PLACE) as *const u32
+    }
+}

crates/misc/py/examples/two_modules/run.py

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+import wasmtime
+import two
+
+print("answer() returned", two.ask())

crates/misc/py/examples/two_modules/two.wat

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+(module
+  (import "one" "memory" (memory $memory 0))
+  (import "one" "bar" (func $bar (result i32)))
+  (export "ask" (func $foo))
+
+  (func $foo (result i32)
+    call $bar
+    ;; Deference returned pointer to the value from imported memory
+    i32.load
+  )
+)