Fix typos

Author: alexcrichton

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -627,14 +627,14 @@ pub fn create_compressed_metadata_file_for_xcoff(
 /// `data`.
 ///
 /// NB: the wasm file format is simple enough that for now an extra crate from
-/// crates.io (such as `wasm-encoder` isn't used at this time (nor `wasmparser`
+/// crates.io (such as `wasm-encoder`) isn't used at this time (nor `wasmparser`
 /// for example to parse). The file format is:
 ///
 /// * 4-byte header "\0asm"
 /// * 4-byte version number - 1u32 in little-endian format
 /// * concatenated sections, which for this object is always "custom sections"
 ///
-/// Custom sections are then defiend by:
+/// Custom sections are then defined by:
 /// * 1-byte section identifier - 0 for a custom section
 /// * leb-encoded section length (size of the contents beneath this bullet)
 ///   * leb-encoded custom section name length
@@ -645,7 +645,7 @@ pub fn create_compressed_metadata_file_for_xcoff(
 /// <https://github.com/WebAssembly/tool-conventions/blob/main/Linking.md>
 /// which is required to inform LLD that this is an object file but it should
 /// otherwise basically ignore it if it otherwise looks at it. The linking
-/// section currently is defined by a single verion byte (2) and then further
+/// section currently is defined by a single version byte (2) and then further
 /// sections, but we have no more sections, so it's just the byte "2".
 ///
 /// The next custom section is the one we're interested in.