[windows] Temporarily guard lifetime dependence diagnostics

by -enable-experimental-feature NonescapableTypes
on the Windows platform

These passes do nothing unless the above feature flag is enabled, so
the only reason to run the pass is to exercise SwiftCompilerSources
and catch invalid SIL.

These passes rely on fundamental SwiftCompilerSources abstractions
which have not yet been tested outside of the passes. They don't yet
handle all SIL patterns, and SIL continues to evolve. We would like to
can these issues quickly as we hit them, but only if we have a way of
reproducing the failure. Currently, we don't have a way of reproducing
Windows-arm64 failures.

Workaround for:
rdar://128434000 ([nonescapable] [LifetimeDependenceInsertion]
Package resolution fails with arm64 Windows toolchain)

Author: atrick

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/LifetimeDependenceDiagnostics.swift

@@ -29,6 +29,11 @@ private func log(prefix: Bool = true, _ message: @autoclosure () -> String) {
 let lifetimeDependenceDiagnosticsPass = FunctionPass(
   name: "lifetime-dependence-diagnostics")
 { (function: Function, context: FunctionPassContext) in
+#if os(Windows)
+  if !context.options.hasFeature(.NonescapableTypes) {
+    return
+  }
+#endif
   log(prefix: false, "\n--- Diagnosing lifetime dependence in \(function.name)")
   log("\(function)")
 

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/LifetimeDependenceInsertion.swift

@@ -31,6 +31,11 @@ private func log(prefix: Bool = true, _ message: @autoclosure () -> String) {
 let lifetimeDependenceInsertionPass = FunctionPass(
   name: "lifetime-dependence-insertion")
 { (function: Function, context: FunctionPassContext) in
+#if os(Windows)
+  if !context.options.hasFeature(.NonescapableTypes) {
+    return
+  }
+#endif
   log(prefix: false, "\n--- Inserting lifetime dependence markers in \(function.name)")
 
   for instruction in function.instructions {

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/LifetimeDependenceScopeFixup.swift

@@ -31,6 +31,11 @@ private func log(prefix: Bool = true, _ message: @autoclosure () -> String) {
 let lifetimeDependenceScopeFixupPass = FunctionPass(
   name: "lifetime-dependence-scope-fixup")
 { (function: Function, context: FunctionPassContext) in
+#if os(Windows)
+  if !context.options.hasFeature(.NonescapableTypes) {
+    return
+  }
+#endif
   log(prefix: false, "\n--- Scope fixup for lifetime dependence in \(function.name)")
 
   let localReachabilityCache = LocalVariableReachabilityCache()