Eliminate dependencies on _SwiftSyntaxMacros having actual macros in it

Author: DougGregor

test/Index/index_macros.swift

@@ -3,9 +3,9 @@
 // REQUIRES: OS=macosx
 
 
-macro myLine: Int = _SwiftSyntaxMacros.LineMacro
-macro myFilename<T: ExpressibleByStringLiteral>: T = _SwiftSyntaxMacros.FilePathMacro
-macro myStringify<T>(_: T) -> (T, String) = _SwiftSyntaxMacros.StringifyMacro
+macro myLine: Int = MacroDefinition.LineMacro
+macro myFilename<T: ExpressibleByStringLiteral>: T = MacroDefinition.FileMacro
+macro myStringify<T>(_: T) -> (T, String) = MacroDefinition.StringifyMacro
 
 func test(x: Int) {
   _ = #myLine

test/Macros/macros_diagnostics.swift

@@ -1,7 +1,9 @@
-// RUN: %target-typecheck-verify-swift -enable-experimental-feature Macros -module-name MacrosTest
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift -I %swift-host-lib-dir -L %swift-host-lib-dir -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
+// RUN: %target-typecheck-verify-swift -enable-experimental-feature Macros -module-name MacrosTest -load-plugin-library %t/%target-library-name(MacroDefinition) -I %swift-host-lib-dir
 // REQUIRES: OS=macosx
 
-macro stringify<T>(_ value: T) -> (T, String) = _SwiftSyntaxMacros.StringifyMacro
+macro stringify<T>(_ value: T) -> (T, String) = MacroDefinition.StringifyMacro
 macro missingMacro1(_: Any) = MissingModule.MissingType // expected-note{{'missingMacro1' declared here}}
 macro missingMacro2(_: Any) = MissingModule.MissingType
 

test/ModuleInterface/macros.swift

@@ -7,14 +7,14 @@
 // RUN: %target-swift-frontend -compile-module-from-interface %t/Macros.swiftinterface -o %t/Macros.swiftmodule
 
 // CHECK: #if compiler(>=5.3) && $Macros
-// CHECK-NEXT: public macro publicStringify<T>(_ value: T) -> (T, Swift.String) = _SwiftSyntaxMacros.StringifyMacro
+// CHECK-NEXT: public macro publicStringify<T>(_ value: T) -> (T, Swift.String) = SomeModule.StringifyMacro
 // CHECK-NEXT: #endif
-public macro publicStringify<T>(_ value: T) -> (T, String) = _SwiftSyntaxMacros.StringifyMacro
+public macro publicStringify<T>(_ value: T) -> (T, String) = SomeModule.StringifyMacro
 
 // CHECK: #if compiler(>=5.3) && $Macros
-// CHECK: public macro publicLine<T>: T = _SwiftSyntaxMacros.Line where T : Swift.ExpressibleByIntegerLiteral
+// CHECK: public macro publicLine<T>: T = SomeModule.Line where T : Swift.ExpressibleByIntegerLiteral
 // CHECK-NEXT: #endif
-public macro publicLine<T: ExpressibleByIntegerLiteral>: T = _SwiftSyntaxMacros.Line
+public macro publicLine<T: ExpressibleByIntegerLiteral>: T = SomeModule.Line
 
 // CHECK-NOT: internalStringify
-macro internalStringify<T>(_ value: T) -> (T, String) = _SwiftSyntaxMacros.StringifyMacro
+macro internalStringify<T>(_ value: T) -> (T, String) = SomeModule.StringifyMacro

test/Serialization/Inputs/def_macros.swift

@@ -1,3 +1,3 @@
-public macro publicStringify<T>(_ value: T) -> (T, String) = _SwiftSyntaxMacros.StringifyMacro
+public macro publicStringify<T>(_ value: T) -> (T, String) = SomeModule.StringifyMacro
 
-macro internalStringify<T>(_ value: T) -> (T, String) = _SwiftSyntaxMacros.StringifyMacro
+macro internalStringify<T>(_ value: T) -> (T, String) = SomeModule.StringifyMacro

test/Serialization/macros.swift

@@ -10,6 +10,7 @@ import def_macros
 
 func test(a: Int, b: Int) {
   _ = #publicStringify(a + b)
+  // expected-error@-1{{external macro implementation type 'SomeModule.StringifyMacro' could not be found for macro 'publicStringify'; the type must be public and provided via '-load-plugin-library'}}
 
   _ = #internalStringify(a + b)
   // expected-error@-1{{macro 'internalStringify' is undefined}}