Update RUSTFLAGS for wasm build script (#584)

Shared memory with Wasm atomics is disabled by default 
since rust-lang/rust#147225. This adds
the necessary flags to enable it.

Author: Wrufesh

hf_xet_wasm/build_wasm.sh

@@ -12,10 +12,24 @@ set -ex
 #   features enabled, ensuring that LLVM will generate atomic instructions,
 #   shared memory, passive segments, etc.
 
-RUSTFLAGS='-C target-feature=+atomics,+bulk-memory,+mutable-globals --cfg getrandom_backend="wasm_js"' \
-    cargo +nightly build --example simple --target wasm32-unknown-unknown --release -Z build-std=std,panic_abort
+RUSTFLAGS="-C target-feature=+atomics,+bulk-memory,+mutable-globals \
+  -C link-arg=--shared-memory \
+  -C link-arg=--max-memory=1073741824 \
+  -C link-arg=--import-memory \
+  -C link-arg=--export=__wasm_init_tls \
+  -C link-arg=--export=__tls_size \
+  -C link-arg=--export=__tls_align \
+  -C link-arg=--export=__tls_base \
+  --cfg getrandom_backend=\"wasm_js\"" \
+cargo +nightly build \
+    --example simple \
+    --target wasm32-unknown-unknown \
+    --release \
+    -Z build-std=std,panic_abort
 
-RUSTFLAGS='--cfg getrandom_backend="wasm_js"' wasm-bindgen \
+# Generate JS/WASM glue for web targets
+RUSTFLAGS='--cfg getrandom_backend="wasm_js"' \
+wasm-bindgen \
     target/wasm32-unknown-unknown/release/examples/simple.wasm \
     --out-dir ./examples/target/ \
     --typescript \