Apply clang-format for core/iwasm compilation and libraries (#784)

Apply clang-format for core/iwasm/compilation and core/iwasm/libraries files.
Add wasm-c-api empty_imports sample to workflow test.
And enable triggering workflow when core/config.h changes.

core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/include/wasmtime_ssp.h

@@ -1,6 +1,8 @@
 /*
- * Part of the Wasmtime Project, under the Apache License v2.0 with LLVM Exceptions.
- * See https://github.com/bytecodealliance/wasmtime/blob/main/LICENSE for license information.
+ * Part of the Wasmtime Project, under the Apache License v2.0 with
+ * LLVM Exceptions. See
+ *   https://github.com/bytecodealliance/wasmtime/blob/main/LICENSE
+ * for license information.
  *
  * This file declares an interface similar to WASI, but augmented to expose
  * some implementation details such as the curfds arguments that we pass
@@ -13,6 +15,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
+/* clang-format off */
+
 #ifdef __cplusplus
 #ifndef _Static_assert
 #define _Static_assert static_assert
@@ -28,7 +32,6 @@
 extern "C" {
 #endif
 
-
 _Static_assert(_Alignof(int8_t) == 1, "non-wasi data layout");
 _Static_assert(_Alignof(uint8_t) == 1, "non-wasi data layout");
 _Static_assert(_Alignof(int16_t) == 2, "non-wasi data layout");
@@ -891,5 +894,6 @@ __wasi_errno_t wasmtime_ssp_sched_yield(void)
 
 #undef WASMTIME_SSP_SYSCALL_NAME
 
-#endif
+/* clang-format on */
 
+#endif /* end of WASMTIME_SSP_H */