[embedded] Add initial tests; fix two issues in IRGen.

Author: zoecarver

lib/IRGen/GenDecl.cpp

@@ -1412,14 +1412,14 @@ deleteAndReenqueueForEmissionValuesDependentOnCanonicalPrespecializedMetadataRec
 void IRGenerator::emitLazyDefinitions() {
   if (SIL.getASTContext().LangOpts.hasFeature(Feature::Embedded)) {
     // In embedded Swift, the compiler cannot emit any metadata, etc.
-    assert(LazyTypeMetadata.empty() &&
-           LazySpecializedTypeMetadataRecords.empty() &&
-           LazyTypeContextDescriptors.empty() &&
-           LazyOpaqueTypeDescriptors.empty() &&
-           LazyFunctionDefinitions.empty() &&
-           LazyCanonicalSpecializedMetadataAccessors.empty() &&
-           LazyMetadataAccessors.empty() &&
-           LazyWitnessTables.empty());
+    LazyTypeMetadata.clear();
+    LazySpecializedTypeMetadataRecords.clear();
+    LazyTypeContextDescriptors.clear();
+    LazyOpaqueTypeDescriptors.clear();
+    LazyFunctionDefinitions.clear();
+    LazyCanonicalSpecializedMetadataAccessors.clear();
+    LazyMetadataAccessors.clear();
+    LazyWitnessTables.clear();
   }
 
   while (!LazyTypeMetadata.empty() ||

lib/SIL/IR/SILSymbolVisitor.cpp

@@ -601,6 +601,9 @@ class SILSymbolVisitorImpl : public ASTVisitor<SILSymbolVisitorImpl> {
     if (canSkipNominal(NTD))
       return;
 
+    if (NTD->getASTContext().LangOpts.hasFeature(Feature::Embedded))
+      return;
+
     auto declaredType = NTD->getDeclaredType()->getCanonicalType();
 
     if (!NTD->getObjCImplementationDecl()) {

test/embedded/basic-errors-no-stdlib.swift

@@ -0,0 +1,9 @@
+// RUN: not %target-swift-frontend -emit-ir %s -parse-stdlib -enable-experimental-feature Embedded 2>&1 | %FileCheck %s
+
+public protocol Player {}
+struct Concrete: Player {}
+
+// CHECK: error: existential can cause metadata allocation or locks
+public func test() -> any Player {
+  Concrete()
+}

test/embedded/basic-irgen-no-stdlib.swift

@@ -0,0 +1,32 @@
+// RUN: %target-swift-emit-ir %s -parse-stdlib -enable-experimental-feature Embedded | %FileCheck %s
+
+struct Bool {}
+
+protocol Player {
+  func play()
+  var canPlay: Bool { get }
+}
+
+struct Concrete : Player {
+  func play() { }
+  var canPlay: Bool { Bool() }
+}
+
+func start(p: some Player) {
+  p.play()
+}
+
+public func main() {
+  start(p: Concrete())
+}
+
+// CHECK-LABEL: declare hidden swiftcc void @"$s4main8ConcreteVACycfC"()
+
+// CHECK-LABEL: declare hidden swiftcc void @"$s4main5start1pyx_tAA6PlayerRzlFAA8ConcreteV_Tg5"()
+
+// CHECK-LABEL: define swiftcc void @"$s4mainAAyyF"()
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    call swiftcc void @"$s4main8ConcreteVACycfC"()
+// CHECK-NEXT:    call swiftcc void @"$s4main5start1pyx_tAA6PlayerRzlFAA8ConcreteV_Tg5"()
+// CHECK-NEXT:    ret void
+// CHECK-NEXT:  }