[Concurrency] Include more pieces of Concurrency in Embedded (AsyncStream, continuations)

We have been only including a subset of files and functionality on Embedded Concurrency, let's instead include all the
source files, and have a fine grained opt out on things that don't yet work. Namely, this is still avoiding clocks, task
sleeping and custom executors.

Add a test for AsyncStream and continuations on Embedded Concurrency.

test/embedded/dependencies-concurrency-custom-executor.swift

@@ -0,0 +1,85 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -target %target-cpu-apple-macos14 -disable-availability-checking -parse-as-library -enable-experimental-feature Embedded %s -c -o %t/a.o
+// RUN: %target-clang -x c -std=c11 -I %swift_obj_root/include -c %S/Inputs/executor.c -o %t/executor.o
+// RUN: %target-clang %t/a.o %t/executor.o -o %t/a.out %swift_obj_root/lib/swift/embedded/%target-cpu-apple-macos/libswift_Concurrency.a -dead_strip
+
+// RUN: grep DEP\: %s | sed 's#// DEP\: ##' | sort > %t/allowed-dependencies.txt
+
+// RUN: %llvm-nm --undefined-only --format=just-symbols %t/a.out | sort | tee %t/actual-dependencies.txt
+
+// Fail if there is any entry in actual-dependencies.txt that's not in allowed-dependencies.txt
+// RUN: test -z "`comm -13 %t/allowed-dependencies.txt %t/actual-dependencies.txt`"
+
+// DEP: __ZNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEE6appendEPKc
+// DEP: __ZNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEE6appendEPKcm
+// DEP: __ZNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEE6insertEmPKc
+// DEP: __ZNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEED1Ev
+// DEP: __ZNSt3__16chrono12steady_clock3nowEv
+// DEP: __ZNSt3__19to_stringEj
+// DEP: __ZNSt3__19to_stringEy
+// DEP: __ZdlPv
+// DEP: __ZdlPvm
+// DEP: __Znwm
+// DEP: ___assert_rtn
+// DEP: ___error
+// DEP: ___stack_chk_fail
+// DEP: ___stack_chk_guard
+// DEP: ___stderrp
+// DEP: _abort
+// DEP: _exit
+// DEP: _fprintf
+// DEP: _free
+// DEP: _malloc
+// DEP: _memmove
+// DEP: _memset
+// DEP: _memset_s
+// DEP: _nanosleep
+// DEP: _posix_memalign
+// DEP: _putchar
+// DEP: _strlen
+// DEP: _vfprintf
+// DEP: _vsnprintf
+// DEP: _write
+
+// RUN: %target-run %t/a.out | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: executable_test
+// REQUIRES: optimized_stdlib
+// REQUIRES: OS=macosx
+
+import _Concurrency
+
+public func test() async -> Int {
+  print("test")
+  let t = Task {
+    print("return 42")
+    return 42
+  }
+  print("await")
+  let v = await t.value
+  print("return")
+  return v
+}
+
+@main
+struct Main {
+  static func main() async {
+    print("main")
+    // CHECK: main
+    let t = Task {
+      print("task")
+      let x = await test()
+      print(x == 42 ? "42" : "???")
+    }
+    print("after task")
+    await t.value
+    // CHECK-NEXT: after task
+    // CHECK-NEXT: task
+    // CHECK-NEXT: test
+    // CHECK-NEXT: await
+    // CHECK-NEXT: return 42
+    // CHECK-NEXT: return
+    // CHECK-NEXT: 42
+  }
+}