[embedded] Fix embedded Swift builds with -Xcc -ffreestanding and -fno-builtin

Author: kubamracek

stdlib/public/SwiftShims/swift/shims/LibcShims.h

@@ -41,8 +41,8 @@ __swift_size_t _swift_stdlib_fwrite_stdout(const void *ptr, __swift_size_t size,
 // General utilities <stdlib.h>
 // Memory management functions
 extern int posix_memalign(void *_Nullable *_Nonnull memptr, __swift_size_t alignment, __swift_size_t size);
+extern void free(void *_Nullable);
 static inline void _swift_stdlib_free(void *_Nullable ptr) {
-  extern void free(void *_Nullable);
   free(ptr);
 }
 

test/embedded/fno-builtin.swift

@@ -0,0 +1,11 @@
+// RUN: %target-swift-emit-ir %s %S/Inputs/print.swift -module-name main -Xcc -fno-builtin -enable-experimental-feature Embedded | %FileCheck %s
+// RUN: %target-swift-emit-ir %s %S/Inputs/print.swift -module-name main -Xcc -ffreestanding -enable-experimental-feature Embedded | %FileCheck %s
+
+public func foo() -> [Int] {
+	var a = [1, 2, 3]
+	a.append(4)
+	let b = a.sorted()
+	return b
+}
+
+// CHECK: define {{.*}}@"$s4main3fooSaySiGyF"()