[Strings] string.is_usv_sequence (#4783)

This implements it as a StringMeasure opcode. They do have the same number of
operands, same trapping behavior, and same return type. They both get a string and
do some inspection of it to return an i32. Perhaps the name could be StringInspect
or something like that, rather than StringMeasure..? But I think for now this might be
good enough, and the spec may change anyhow later.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/wasm/wasm-stack.cpp b/src/wasm/wasm-stack.cpp
index 9a5db2928..e1b093b26 100644
--- a/src/wasm/wasm-stack.cpp
+++ b/src/wasm/wasm-stack.cpp
@@ -2276,6 +2276,9 @@ void BinaryInstWriter::visitStringMeasure(StringMeasure* curr) {
     case StringMeasureWTF16:
       o << U32LEB(BinaryConsts::StringMeasureWTF16);
       break;
+    case StringMeasureIsUSV:
+      o << U32LEB(BinaryConsts::StringIsUSV);
+      break;
     default:
       WASM_UNREACHABLE("invalid string.new*");
   }