unittests/ASM: Adds test case for AVX scalar round with insert bug

unittests/ASM/FEX_bugs/vroundscalar_sve256.asm

@@ -0,0 +1,27 @@
+%ifdef CONFIG
+{
+  "RegData": {
+    "XMM0": ["0x818283843f800000", "0x9192939495969798", "0x0000000000000000", "0x0000000000000000"]
+  }
+}
+%endif
+
+; FEX-Emu had a bug in its 256-bit SVE implementation of AVX where scalar round with insert wasn't inserting correctly.
+; This tests to ensure that the sources are merged correctly.
+vmovaps ymm0, [rel .data_trash]
+vmovaps ymm1, [rel .data_trash + 32]
+
+vroundss xmm0, xmm1, [rel .data], 00000010b ; +inf
+
+hlt
+
+align 4096
+.data:
+dd 0.5, -0.5, 1.5, -1.5
+dd 0.5, -0.5, 1.5, -1.5
+
+.data_trash:
+dq 0x4142434445464748, 0x5152535455565758
+dq 0x6162636465666768, 0x7172737475767778
+dq 0x8182838485868788, 0x9192939495969798
+dq 0xA1A2A3A4A5A6A7A8, 0xB1B2B3B4B5B6B7B8