Add tests for 80-bit FLD/FST instructions

Author: mrexodia

tests/X86/X87/FLD.S

@@ -27,6 +27,13 @@ TEST_INPUTS(TEST_INPUTS_MMX_QWORD)
     fld QWORD PTR [rsp]
 TEST_END_64
 
+TEST_BEGIN_64(FLDm80, 1)
+TEST_INPUTS(0x0123456789ABCDEF)
+    mov QWORD PTR [rsp], ARG1_64
+    mov WORD PTR [rsp + 8], 0x1337
+    fld TBYTE PTR [rsp]
+TEST_END_64
+
 TEST_BEGIN_64(FLDst0, 1)
 TEST_INPUTS(TEST_INPUTS_MMX_QWORD)
     push ARG1_64

tests/X86/X87/FST.S

@@ -49,6 +49,17 @@ FST_INPUTS
     fst QWORD PTR [rsp]
 TEST_END_64
 
+TEST_BEGIN_64(FSTm80, 1)
+TEST_INPUTS(0x0123456789ABCDEF)
+    mov QWORD PTR [rsp], ARG1_64
+    mov WORD PTR [rsp + 8], 0x1337
+    fld TBYTE PTR [rsp]
+    mov WORD PTR [rsp + 8], 0x0
+    fst TBYTE PTR [rsp]
+    mov rax, QWORD PTR [rsp]
+    movzx rbx, WORD PTR [rsp + 8]
+TEST_END_64
+
 TEST_BEGIN_64(FSTst, 1)
 FST_INPUTS