Support reference types in the DWARF transform (#1986)

tests/all/debug/testsuite/fraction-norm.cc

@@ -0,0 +1,40 @@
+// Compile with:
+//   clang++ --target=wasm32 fraction-norm.cc -o fraction-norm.wasm -g \
+//     -O0 -nostdlib -fdebug-prefix-map=$PWD=.
+
+struct Fraction {
+  long numerator;
+  long denominator;
+};
+
+inline long abs(long x)
+{
+  return x >= 0 ? x : -x;  
+}
+
+extern "C"
+void norm(Fraction &n)
+{
+  long a = abs(n.numerator), b = abs(n.denominator);
+  if (a == 0 || b == 0) return;
+  do {
+   a %= b;
+   if (a == 0) break;
+   b %= a;
+  } while (b > 0);
+  long gcd = a + b;
+  if (n.denominator > 0) {
+    n.numerator /= gcd;
+    n.denominator /= gcd;
+  } else {
+    n.numerator /= -gcd;
+    n.denominator /= -gcd;
+  }
+}
+
+extern "C"
+void _start()
+{
+  Fraction c = {6, 27};
+  norm(c);
+}