Fix windows libclang lookup

Author: owenv

Sources/SWBCore/SpecImplementations/Tools/CCompiler.swift

@@ -967,10 +967,10 @@ public class ClangCompilerSpec : CompilerSpec, SpecIdentifierType, GCCCompatible
 
                 // If not defined, try to find one from the toolchain.
                 var candidatesSkipped: [Path] = []
-                for (toolchainPath, toolchainLibrarySearchPath) in cbc.producer.toolchains.map({ ($0.path, $0.librarySearchPaths) }) {
-                    if let path = toolchainLibrarySearchPath.findLibrary(operatingSystem: cbc.producer.hostOperatingSystem, basename: "clang") {
+                for toolchain in cbc.producer.toolchains {
+                    if let path = try? toolchain.lookup(subject: .library(basename: "clang"), operatingSystem: cbc.producer.hostOperatingSystem) {
                         // Check that this is the same toolchain and version as the compiler. Mismatched clang/libclang is not supported with explicit modules.
-                        let compilerAndLibraryAreInSameToolchain = toolchainPath.isAncestor(of: compiler)
+                        let compilerAndLibraryAreInSameToolchain = toolchain.path.isAncestor(of: compiler)
                         let libclangVersion = cbc.producer.lookupLibclang(path: path).version
                         // On macOS we enforce a matching clang and libclang version, the versioning schemes on other host platforms currently make this difficult.
                         let compilerAndLibraryVersionsMatch = libclangVersion != nil && libclangVersion == clangInfo?.clangVersion || cbc.producer.hostOperatingSystem != .macOS