A32: Implement Thumb-1 variant of WFE

src/frontend/A32/decoder/thumb16.h

@@ -90,6 +90,7 @@ std::optional<std::reference_wrapper<const Thumb16Matcher<V>>> DecodeThumb16(u16
         // Hint instructions
         INST(&V::thumb16_NOP,            "NOP",                      "1011111100000000"), // v6T2
         INST(&V::thumb16_SEV,            "SEV",                      "1011111101000000"), // v7
+        INST(&V::thumb16_WFE,            "WFE",                      "1011111100100000"), // v7
 
         // Miscellaneous 16-bit instructions
         INST(&V::thumb16_SXTH,           "SXTH",                     "1011001000mmmddd"), // v6

src/frontend/A32/disassembler/disassembler_thumb.cpp

@@ -254,6 +254,10 @@ public:
         return "sev";
     }
 
+    std::string thumb16_WFE() {
+        return "wfe";
+    }
+
     std::string thumb16_SXTH(Reg m, Reg d) {
         return fmt::format("sxth {}, {}", d, m);
     }

src/frontend/A32/translate/translate_thumb.cpp

@@ -684,6 +684,11 @@ struct ThumbTranslatorVisitor final {
         return RaiseException(Exception::SendEvent);
     }
 
+    // WFE<c>
+    bool thumb16_WFE() {
+        return RaiseException(Exception::WaitForEvent);
+    }
+
     // SXTH <Rd>, <Rm>
     // Rd cannot encode R15.
     bool thumb16_SXTH(Reg m, Reg d) {