Add cmake compatibility to c-api (#4369)

* Add cmake compatibility to c-api

* Add CMake documentation to wasmtime.h

* Add CMake instructions in examples

* Modify CI for CMake support

* Use correct rust in CI

* Trigger build

* Refactor run-examples

* Reintroduce example_to_run in run-examples

* Replace run-examples crate with cmake

* Fix markdown formatting in examples readme

* Fix cmake test quotes

* Build rust wasm before cmake tests

* Pass CTEST_OUTPUT_ON_FAILURE

* Another cmake test

* Handle os differences in cmake test

* Fix bugs in memory and multimemory examples

crates/c-api/include/wasmtime.h

@@ -28,6 +28,22 @@
  * as a `lib` directory with both a static archive and a dynamic library of
  * Wasmtime. You can link to either of them as you see fit.
  *
+ * ## Installing the C API through CMake
+ *
+ * CMake can be used to make the process of linking and compiling easier. An
+ * example of this if you have wasmtime as a git submodule at
+ * `third_party/wasmtime`:
+ * ```
+ * add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/third_party/wasmtime/crates/c-api
+ * ${CMAKE_CURRENT_BINARY_DIR}/wasmtime)
+ * ...
+ * target_include_directories(YourProject PUBLIC wasmtime)
+ * target_link_libraries(YourProject PUBLIC wasmtime)
+ * ```
+ * `BUILD_SHARED_LIBS` is provided as a define if you would like to build a
+ * shared library instead. You must distribute the appropriate shared library
+ * for your platform if you do this.
+ *
  * ## Linking against the C API
  *
  * You'll want to arrange the `include` directory of the C API to be in your
@@ -166,8 +182,8 @@
 
 #include <wasi.h>
 #include <wasmtime/config.h>
-#include <wasmtime/error.h>
 #include <wasmtime/engine.h>
+#include <wasmtime/error.h>
 #include <wasmtime/extern.h>
 #include <wasmtime/func.h>
 #include <wasmtime/global.h>