docs: Update LLVM backend status and add comptime parameter support

- Mark LLVM AOT backend as core complete (functions, structs, generics)
- Add recent progress for LLVM backend (parameter mapping, InsertValue, ExtractValue)
- Document comptime parameter support in Zig grammar
- Update roadmap to reflect LLVM backend completion
- Update multi-backend description to show LLVM is fully working

Author: darmie

BACKLOG.md

@@ -1,10 +1,15 @@
 # Zyntax Compiler - Development Backlog
 
-**Last Updated**: November 23, 2025
+**Last Updated**: November 27, 2025
 **Current Status**: Production-Ready Core (100% tests passing, 71/71 Zig tests)
 
 **Recent Progress**:
 
+- ✅ **LLVM Backend Working** (AOT and JIT modes fully functional - functions, structs, generics)
+  - Parameter value mapping for function calls
+  - Struct initialization with InsertValue
+  - Generic function instantiation with comptime
+- ✅ **Comptime Parameter Support** (Zig grammar: `fn foo(comptime T: type, x: T) T`)
 - ✅ **ZynPEG VM Runtime** (No Rust compilation required! JSON command pattern for dynamic AST construction)
   - `pest_vm` for dynamic grammar parsing
   - JSON action blocks in `.zyn` files → runtime interpretation
@@ -199,14 +204,26 @@ No Rust compilation required for grammar users! Dynamic interpretation of JSON a
 
 ## Compiler Infrastructure
 
-### 2. LLVM AOT Backend (MEDIUM PRIORITY)
-**Status**: Framework exists, needs completion
+### 2. LLVM AOT Backend (MEDIUM PRIORITY) ✅ CORE COMPLETE
+
+**Status**: Working for core features (functions, structs, generics)
 **Location**: `crates/compiler/src/llvm_backend.rs`
 
+**Completed (November 27, 2025)**:
+
+- [x] Function calls with parameters (SSA parameter value mapping)
+- [x] Struct initialization (InsertValue instruction)
+- [x] Struct field access (ExtractValue instruction)
+- [x] Generic function instantiation with comptime
+- [x] Both AOT and JIT modes working
+- [x] Basic control flow (if/while)
+- [x] Arithmetic operations
+
 **Remaining Work**:
-- [ ] Complete instruction translation
+
+- [ ] Advanced control flow (switch, pattern matching)
+- [ ] Error union types (try/catch)
 - [ ] Implement optimization passes
-- [ ] Generate executable binaries
 - [ ] Cross-platform testing
 
 ### 3. Bytecode Interpreter (LOW PRIORITY)

README.md

@@ -24,7 +24,7 @@
 
 - **Production-Ready stdlib**: Vec, String, HashMap, Iterator (93/100 functions compile)
 
-- **Multi-Backend**: Cranelift JIT (fast) + LLVM AOT (optimized)
+- **Multi-Backend**: Cranelift JIT (fast) + LLVM AOT/JIT (optimized, fully working)
 
 - **HIR Builder API**: Type-safe, fluent interface for IR construction
 
@@ -472,9 +472,10 @@ cargo build --release
 #### ✅ Tiered JIT Compilation
 - **Tier 1**: Cranelift baseline JIT (fast compilation)
 - **Tier 2**: Cranelift optimized (moderate optimizations)
-- **Tier 3**: LLVM JIT (aggressive optimizations for hot paths)
+- **Tier 3**: LLVM JIT (aggressive optimizations for hot paths) - **fully working**
 - Runtime profiling with atomic execution counters
 - Hot-path detection and automatic recompilation
+- LLVM AOT backend for native executables (functions, structs, generics)
 
 #### ✅ Standard Library
 - `Vec<T>` - Dynamic array with push/pop/indexing
@@ -551,7 +552,8 @@ See [BACKLOG.md](BACKLOG.md) for detailed tasks.
 
 ### Q1 2026: Production Features
 
-- 🔄 LLVM AOT backend completion
+- ✅ LLVM AOT/JIT backend core complete (functions, structs, generics, control flow)
+- 🔄 LLVM backend: advanced features (switch, pattern matching, error unions)
 - 🔄 Haxe-style exception handling (throw/catch/finally with stack unwinding)
 - 🔄 Complete I/O and networking standard library
 - 🔄 String operations (needs stdlib integration via plugin system)