docs: add BARRIER to supported words list in CLAUDE.md

Author: tetsuo-cpp

CLAUDE.md

@@ -87,7 +87,7 @@ uv run ruff format gpu_test/
 
 - **Stack Type**: `!forth.stack` - untyped stack, programmer ensures type safety
 - **Operations**: All take stack as input and produce stack as output (except `forth.stack`)
-- **Supported Words**: literals (integer `42` and float `3.14`), `DUP DROP SWAP OVER ROT NIP TUCK PICK ROLL`, `+ - * / MOD`, `F+ F- F* F/` (float arithmetic), `FEXP FSQRT FLOG FABS FNEG` (float math intrinsics), `FMAX FMIN` (float min/max), `AND OR XOR NOT LSHIFT RSHIFT`, `= < > <> <= >= 0=`, `F= F< F> F<> F<= F>=` (float comparison), `S>F F>S` (int/float conversion), `@ !` (global memory), `F@ F!` (float global memory), `S@ S!` (shared memory), `SF@ SF!` (float shared memory), `I8@ I8! SI8@ SI8!` (i8 memory), `I16@ I16! SI16@ SI16!` (i16 memory), `I32@ I32! SI32@ SI32!` (i32 memory), `HF@ HF! SHF@ SHF!` (f16 memory), `BF@ BF! SBF@ SBF!` (bf16 memory), `F32@ F32! SF32@ SF32!` (f32 memory), `CELLS`, `IF ELSE THEN`, `BEGIN UNTIL`, `BEGIN WHILE REPEAT`, `DO LOOP +LOOP I J K`, `LEAVE UNLOOP EXIT`, `{ a b -- }` (local variables in word definitions), `TID-X/Y/Z BID-X/Y/Z BDIM-X/Y/Z GDIM-X/Y/Z GLOBAL-ID` (GPU indexing).
+- **Supported Words**: literals (integer `42` and float `3.14`), `DUP DROP SWAP OVER ROT NIP TUCK PICK ROLL`, `+ - * / MOD`, `F+ F- F* F/` (float arithmetic), `FEXP FSQRT FLOG FABS FNEG` (float math intrinsics), `FMAX FMIN` (float min/max), `AND OR XOR NOT LSHIFT RSHIFT`, `= < > <> <= >= 0=`, `F= F< F> F<> F<= F>=` (float comparison), `S>F F>S` (int/float conversion), `@ !` (global memory), `F@ F!` (float global memory), `S@ S!` (shared memory), `SF@ SF!` (float shared memory), `I8@ I8! SI8@ SI8!` (i8 memory), `I16@ I16! SI16@ SI16!` (i16 memory), `I32@ I32! SI32@ SI32!` (i32 memory), `HF@ HF! SHF@ SHF!` (f16 memory), `BF@ BF! SBF@ SBF!` (bf16 memory), `F32@ F32! SF32@ SF32!` (f32 memory), `CELLS`, `IF ELSE THEN`, `BEGIN UNTIL`, `BEGIN WHILE REPEAT`, `DO LOOP +LOOP I J K`, `LEAVE UNLOOP EXIT`, `{ a b -- }` (local variables in word definitions), `TID-X/Y/Z BID-X/Y/Z BDIM-X/Y/Z GDIM-X/Y/Z GLOBAL-ID` (GPU indexing), `BARRIER` (thread block synchronization).
 - **Float Literals**: Numbers containing `.` or `e`/`E` are parsed as f64 (e.g. `3.14`, `-2.0`, `1.0e-5`, `1e3`). Stored on the stack as i64 bit patterns; F-prefixed words perform bitcast before/after operations.
 - **Kernel Parameters**: Declared in the `\!` header. `\! kernel <name>` is required and must appear first. `\! param <name> i64[<N>]` becomes a `memref<Nxi64>` argument; `\! param <name> i64` becomes an `i64` argument. `\! param <name> f64[<N>]` becomes a `memref<Nxf64>` argument; `\! param <name> f64` becomes an `f64` argument (bitcast to i64 when pushed to stack). Using a param name in code emits `forth.param_ref` (arrays push address; scalars push value).
 - **Shared Memory**: `\! shared <name> i64[<N>]` or `\! shared <name> f64[<N>]` declares GPU shared (workgroup) memory. Emits a tagged `memref.alloca` at kernel entry; ForthToGPU converts it to a `gpu.func` workgroup attribution. Using the shared name in code pushes its base address onto the stack. Use `S@`/`S!` for i64 or `SF@`/`SF!` for f64 shared accesses. Cannot be referenced inside word definitions.