feat(asm): encode the GETCALLERPC, REM, DWORD and half-FCVT shapes

Assisted-by: GLM 5.3 Flash

asm/arm64_encode.go

@@ -595,6 +595,10 @@ func init() {
 		"FNEGS": 0x1e214000, "FNEGD": 0x1e614000,
 		"FSQRTS": 0x1e21c000, "FSQRTD": 0x1e61c000,
 		"FCVTSD": 0x1e22c000, "FCVTDS": 0x1e624000,
+		// The half-precision conversions: FPOP1S rows with the half source
+		// or destination (type 3), single and double beside them.
+		"FCVTHS": 0x1ee24000, "FCVTHD": 0x1ee2c000,
+		"FCVTSH": 0x1e23c000, "FCVTDH": 0x1e63c000,
 		"FRINTNS": 0x1e244000, "FRINTND": 0x1e644000,
 		"FRINTPS": 0x1e24c000, "FRINTPD": 0x1e64c000,
 		"FRINTMS": 0x1e254000, "FRINTMD": 0x1e654000,