Update Emscripten system types

These changes bring the types up to parity with recent Emscripten
versions using the upstream LLVM wasm backend. These changes should be
coordinated with the upgrade of rustc's Emscripten support. See
https://internals.rust-lang.org/t/upgrading-rust-s-emscripten-support/10684

src/unix/linux_like/emscripten/mod.rs

@@ -5,8 +5,8 @@ pub type dev_t = u32;
 pub type socklen_t = u32;
 pub type pthread_t = c_ulong;
 pub type mode_t = u32;
-pub type ino64_t = u32;
-pub type off64_t = i32;
+pub type ino64_t = u64;
+pub type off64_t = i64;
 pub type blkcnt64_t = i32;
 pub type rlim64_t = u64;
 pub type shmatt_t = ::c_ulong;
@@ -16,14 +16,14 @@ pub type msglen_t = ::c_ulong;
 pub type nfds_t = ::c_ulong;
 pub type nl_item = ::c_int;
 pub type idtype_t = ::c_uint;
-pub type loff_t = i32;
+pub type loff_t = i64;
 pub type pthread_key_t = ::c_uint;
 
 pub type clock_t = c_long;
 pub type time_t = c_long;
 pub type suseconds_t = c_long;
 pub type ino_t = u32;
-pub type off_t = i32;
+pub type off_t = i64;
 pub type blkcnt_t = i32;
 
 pub type blksize_t = c_long;