Disable macro on windows (#71685)

On windows (PECOFF), the `static let` properties produced by `DebugDescriptionMacro` 
are not constants, and as a result the `@_section` macro cannot be applied. The error 
message is:

> global variable must be a compile-time constant to use `@_section` attribute

Until this issue is addressed, DebugDescriptionMacro is disabled for windows targets.

Author: kastiglione

lib/Macros/Sources/SwiftMacros/DebugDescriptionMacro.swift

@@ -213,17 +213,17 @@ extension _DebugDescriptionPropertyMacro: PeerMacro {
 
     // Serialize the type summary into a global record, in a custom section, for LLDB to load.
     let decl: DeclSyntax = """
+        #if !os(Windows)
         #if os(Linux)
         @_section(".lldbsummaries")
-        #elseif os(Windows)
-        @_section(".lldbsummaries")
         #else
         @_section("__TEXT,__lldbsummaries")
         #endif
         @_used
         static let _lldb_summary = (
             \(raw: encodeTypeSummaryRecord(typeIdentifier, summaryString))
         )
+        #endif
         """
 
     return [decl]

test/Macros/DebugDescription/linkage.swift

@@ -8,13 +8,18 @@
 struct MyStruct: CustomDebugStringConvertible {
   var debugDescription: String { "thirty" }
 }
+// CHECK: #if !os(Windows)
 // CHECK: #if os(Linux)
 // CHECK: @_section(".lldbsummaries")
-// CHECK: #elseif os(Windows)
-// CHECK: @_section(".lldbsummaries")
 // CHECK: #else
 // CHECK: @_section("__TEXT,__lldbsummaries")
 // CHECK: #endif
 // CHECK: @_used
 // CHECK: static let _lldb_summary = (
+// CHECK:     /* version */ 1 as UInt8,
+// CHECK:     /* record size */ 23 as UInt8,
+// CHECK:     /* "main.MyStruct" */ 14 as UInt8, 109 as UInt8, 97 as UInt8, 105 as UInt8, 110 as UInt8, 46 as UInt8, 77 as UInt8, 121 as UInt8, 83 as UInt8, 116 as UInt8, 114 as UInt8, 117 as UInt8, 99 as UInt8, 116 as UInt8, 0 as UInt8,
+// CHECK:     /* "thirty" */ 7 as UInt8, 116 as UInt8, 104 as UInt8, 105 as UInt8, 114 as UInt8, 116 as UInt8, 121 as UInt8, 0 as UInt8
+// CHECK: )
+// CHECK: #endif