Windows ARM runner and build fixes

[Xarbirus]

I would like to add several fixes for building the repo on Windows ARM, as well as a CI runner for automated build control.

• fix error C2078: too many initializers with ggml_vld1q_u32 with a macro for MSVC ARM64
• fix error C2065: '__fp16': undeclared identifier
• suppress warning C4146: unary minus operator applied to unsigned type, result still unsigned

[ggerganov]

It would call vld1q_f16 with uint16_t * argument.
Does this produce correct results?

[ggerganov]

Does this produce correct results?

Hm, yes - no reason not to.

Wouldn't it be better if instead of introducing ggml_fp16_internal_t, we simply change these to:

diff --git a/ggml.c b/ggml.c
index 80efa6f2..ac0d15b2 100644
--- a/ggml.c
+++ b/ggml.c
@@ -857,7 +857,7 @@ inline static float vaddvq_f32(float32x4_t v) {
     #define GGML_F16x8              float16x8_t
     #define GGML_F16x8_ZERO         vdupq_n_f16(0.0f)
     #define GGML_F16x8_SET1(x)      vdupq_n_f16(x)
-    #define GGML_F16x8_LOAD(x)      vld1q_f16((const __fp16 *)(x))
+    #define GGML_F16x8_LOAD(x)      vld1q_f16((const uint16_t *)(x))
     #define GGML_F16x8_STORE        vst1q_f16
     #define GGML_F16x8_FMA(a, b, c) vfmaq_f16(a, b, c)
     #define GGML_F16x8_ADD          vaddq_f16
@@ -900,7 +900,7 @@ inline static float vaddvq_f32(float32x4_t v) {
     #define GGML_F32Cx4              float32x4_t
     #define GGML_F32Cx4_ZERO         vdupq_n_f32(0.0f)
     #define GGML_F32Cx4_SET1(x)      vdupq_n_f32(x)
-    #define GGML_F32Cx4_LOAD(x)      vcvt_f32_f16(vld1_f16((const __fp16 *)(x)))
+    #define GGML_F32Cx4_LOAD(x)      vcvt_f32_f16(vld1_f16((const uint16_t *)(x)))
     #define GGML_F32Cx4_STORE(x, y)  vst1_f16(x, vcvt_f16_f32(y))
     #define GGML_F32Cx4_FMA(a, b, c) vfmaq_f32(a, b, c)
     #define GGML_F32Cx4_ADD          vaddq_f32

[Xarbirus]

We'll get some warnings (like incompatible pointer types assigning to 'const __fp16 *' from 'const uint16_t *') from GGML_F16_VEC_LOAD in this case.

But if it's ok, I'll commit the change.

[ggerganov]

Let's keep it like proposed