Replace more miscellaenous read_wasm utilities with wat::parse_file. (#601)

crates/test-programs/Cargo.toml

@@ -22,3 +22,4 @@ pretty_env_logger = "0.3.0"
 tempfile = "3.1.0"
 os_pipe = "0.9"
 anyhow = "1.0.19"
+wat = "1.0.2"

crates/test-programs/build.rs

@@ -127,7 +127,7 @@ fn write_testsuite_tests(out: &mut File, dir_entry: DirEntry, testsuite: &str) -
         "        let path = std::path::Path::new(r#\"{}\"#);",
         path.display()
     )?;
-    writeln!(out, "        let data = utils::read_wasm(path)?;")?;
+    writeln!(out, "        let data = wat::parse_file(path)?;")?;
     writeln!(
         out,
         "        let bin_name = utils::extract_exec_name_from_path(path)?;"

crates/test-programs/tests/wasm_tests/utils.rs

@@ -1,16 +1,6 @@
-use std::fs;
 use std::path::Path;
 use tempfile::{Builder, TempDir};
 
-pub fn read_wasm(path: &Path) -> anyhow::Result<Vec<u8>> {
-    let data = fs::read(path)?;
-    if data.starts_with(&[b'\0', b'a', b's', b'm']) {
-        Ok(data)
-    } else {
-        anyhow::bail!("Invalid Wasm file encountered")
-    }
-}
-
 pub fn prepare_workspace(exe_name: &str) -> anyhow::Result<TempDir> {
     let prefix = format!("wasi_common_{}", exe_name);
     let tempdir = Builder::new().prefix(&prefix).tempdir()?;