Fix Windows CI round 3: dirent.h, stdatomic, VLA, M_PI

- tq_convert.c: guard dirent.h with #ifndef _WIN32
- quant.h: add _MSC_VER stdatomic shim (interlocked intrinsics)
- quant.c: fix timespec guard for MSVC CRT
- test_threading.cpp: replace VLA with std::vector (MSVC no VLA)
- test_adaptive.cpp: add _USE_MATH_DEFINES for M_PI

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: unamedkr

quant.h

@@ -104,7 +104,16 @@ const char* quant_version(void);
 #include <mach/mach_time.h>
 #endif
 
+#if defined(_MSC_VER)
+/* MSVC: use interlocked intrinsics */
+#include <intrin.h>
+typedef volatile long atomic_int;
+#define atomic_store(p, v) _InterlockedExchange((p), (v))
+#define atomic_load(p) _InterlockedCompareExchange((p), 0, 0)
+#define atomic_fetch_add(p, v) _InterlockedExchangeAdd((p), (v))
+#else
 #include <stdatomic.h>
+#endif
 
 #ifdef __ARM_NEON
 #include <arm_neon.h>

tests/test_adaptive.cpp

@@ -1,3 +1,5 @@
+#define _USE_MATH_DEFINES
+#include <cmath>
 /**
  * test_adaptive.cpp -- Tests for adaptive compression features
  *

tests/test_threading.cpp

@@ -97,7 +97,8 @@ TEST(Threading, ConcurrentAttention) {
             for (int i = 0; i < 128; i++)
                 query[i] = cosf(i * 0.1f + t);
 
-            float scores[seq_len];
+            std::vector<float> scores_vec(seq_len);
+            float* scores = scores_vec.data();
             tq_status s = tq_attention(ctx, query, blocks.data(),
                                        seq_len, head_dim,
                                        TQ_TYPE_POLAR_3B, scores);

tools/quant.c

@@ -43,7 +43,7 @@
 #ifndef CLOCK_MONOTONIC
 #define CLOCK_MONOTONIC 1
 #endif
-#ifndef _TIMESPEC_DEFINED
+#if defined(_WIN32) && !defined(_TIMESPEC_DEFINED)
 #define _TIMESPEC_DEFINED
 struct timespec { long tv_sec; long tv_nsec; };
 #endif

tools/tq_convert.c

@@ -17,7 +17,9 @@
 #ifndef _WIN32
 #include <unistd.h>
 #endif
+#ifndef _WIN32
 #include <dirent.h>
+#endif
 
 static void print_usage(const char* prog) {
     fprintf(stderr, "TQM Converter — Pre-quantize models for instant loading\n\n");