Instead of importing platform SDK modules, just use C shims

Author: rintaro

Sources/SwiftCompilerPluginMessageHandling/JSON/JSONDecoding.swift

@@ -11,21 +11,9 @@
 //===----------------------------------------------------------------------===//
 
 #if swift(>=6.0)
-#if canImport(Darwin)
-private import Darwin
-#elseif canImport(Glibc)
-private import Glibc
-#elseif canImport(ucrt)
-private import ucrt
-#endif
+private import _SwiftSyntaxCShims
 #else
-#if canImport(Darwin)
-import Darwin
-#elseif canImport(Glibc)
-import Glibc
-#elseif canImport(ucrt)
-import ucrt
-#endif
+import _SwiftSyntaxCShims
 #endif
 
 func decodeFromJSON<T: Decodable>(json: UnsafeBufferPointer<UInt8>) throws -> T {

Sources/SwiftCompilerPluginMessageHandling/StandardIOMessageConnection.swift

@@ -12,22 +12,8 @@
 
 #if swift(>=6.0)
 private import _SwiftSyntaxCShims
-#if canImport(Darwin)
-private import Darwin
-#elseif canImport(Glibc)
-private import Glibc
-#elseif canImport(ucrt)
-private import ucrt
-#endif
 #else
 import _SwiftSyntaxCShims
-#if canImport(Darwin)
-import Darwin
-#elseif canImport(Glibc)
-import Glibc
-#elseif canImport(ucrt)
-import ucrt
-#endif
 #endif
 
 #if canImport(ucrt)

Sources/SwiftSyntax/SyntaxText.swift

@@ -11,25 +11,9 @@
 //===----------------------------------------------------------------------===//
 
 #if swift(>=6.0)
-#if canImport(Darwin)
-private import Darwin
-#elseif canImport(Glibc)
-private import Glibc
-#elseif canImport(Musl)
-private import Musl
-#elseif canImport(ucrt)
-private import ucrt
-#endif
+private import _SwiftSyntaxCShims
 #else
-#if canImport(Darwin)
-import Darwin
-#elseif canImport(Glibc)
-import Glibc
-#elseif canImport(Musl)
-import Musl
-#elseif canImport(ucrt)
-import ucrt
-#endif
+import _SwiftSyntaxCShims
 #endif
 
 /// Represent a string.