A32: Implement Thumb-1 variant of NOP

src/frontend/A32/decoder/thumb16.h

@@ -87,6 +87,9 @@ std::optional<std::reference_wrapper<const Thumb16Matcher<V>>> DecodeThumb16(u16
         INST(&V::thumb16_ADD_sp_t2,      "ADD (SP plus imm, T2)",    "101100000vvvvvvv"), // v4T
         INST(&V::thumb16_SUB_sp,         "SUB (SP minus imm)",       "101100001vvvvvvv"), // v4T
 
+        // Hint instructions
+        INST(&V::thumb16_NOP,            "NOP",                      "1011111100000000"), // v6T2
+
         // Miscellaneous 16-bit instructions
         INST(&V::thumb16_SXTH,           "SXTH",                     "1011001000mmmddd"), // v6
         INST(&V::thumb16_SXTB,           "SXTB",                     "1011001001mmmddd"), // v6

src/frontend/A32/disassembler/disassembler_thumb.cpp

@@ -246,6 +246,10 @@ public:
         return fmt::format("sub sp, sp, #{}", imm32);
     }
 
+    std::string thumb16_NOP() {
+        return "nop";
+    }
+
     std::string thumb16_SXTH(Reg m, Reg d) {
         return fmt::format("sxth {}, {}", d, m);
     }

src/frontend/A32/translate/translate_thumb.cpp

@@ -667,6 +667,11 @@ struct ThumbTranslatorVisitor final {
         return true;
     }
 
+    // NOP<c>
+    bool thumb16_NOP() {
+        return true;
+    }
+
     // SXTH <Rd>, <Rm>
     // Rd cannot encode R15.
     bool thumb16_SXTH(Reg m, Reg d) {