[ddc] Change ! failure to a throw TypeError

Fixes test failures in language/unsorted/inv_cse_licm_test

Change-Id: If8df024d0128568e1f65463d4a82fa593b5a6a1d
Fixes: #42443
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/153481
Reviewed-by: Mark Zhou <[email protected]>
Commit-Queue: Nicholas Shahan <[email protected]>

pkg/dev_compiler/lib/src/kernel/compiler.dart

@@ -5212,8 +5212,9 @@ class ProgramCompiler extends ComputeOnceConstantVisitor<js_ast.Expression>
   @override
   js_ast.Expression visitNullCheck(NullCheck node) {
     var expr = node.operand;
+    var jsExpr = _visitExpression(expr);
     // If the expression is non-nullable already, this is a no-op.
-    return isNullable(expr) ? notNull(expr) : _visitExpression(expr);
+    return isNullable(expr) ? runtimeCall('nullCheck(#)', [jsExpr]) : jsExpr;
   }
 
   @override

sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart

@@ -474,7 +474,9 @@ asInt(obj) {
 
 asNullableInt(obj) => obj == null ? null : asInt(obj);
 
-/// Checks that `x` is not null or undefined.
+/// Checks for null or undefined and returns [x].
+///
+/// Throws [NoSuchMethodError] when it is null or undefined.
 //
 // TODO(jmesserly): inline this, either by generating it as a function into
 // the module, or via some other pattern such as:
@@ -487,12 +489,13 @@ _notNull(x) {
   return x;
 }
 
-/// Checks that `x` is not null or undefined.
+/// Checks for null or undefined and returns [x].
+///
+/// Throws a [TypeError] when [x] is null or undefined (under sound null safety
+/// mode) or emits a runtime warning (otherwise).
 ///
-/// Unlike `_notNull`, this throws a `CastError` (under strict checking)
-/// or emits a runtime warning (otherwise).  This is only used by the
-/// compiler when casting from nullable to non-nullable variants of the
-/// same type.
+/// This is only used by the compiler when casting from nullable to non-nullable
+/// variants of the same type.
 nullCast(x, type) {
   if (x == null) {
     if (!strictNullSafety) {
@@ -504,6 +507,16 @@ nullCast(x, type) {
   return x;
 }
 
+/// Checks for null or undefined and returns [x].
+///
+/// Throws a [TypeError] when [x] is null or undefined.
+///
+/// This is only used by the compiler for the runtime null check operator `!`.
+nullCheck(x) {
+  if (x == null) throw TypeErrorImpl("Unexpected null value.");
+  return x;
+}
+
 /// The global constant map table.
 final constantMaps = JS<Object>('!', 'new Map()');