fix(ivy): correct ngtsc path handling in Windows (#26703)

As it turns out, the usage of path.posix does not unify path handling
across operating systems. Instead, canonical-path is used to ensure
path handling is consistent, avoiding incorrect paths in Windows.

See https://github.com/angular/angular/pull/25862#discussion_r216157914

PR Close #26703

packages/compiler-cli/src/ngtsc/testing/BUILD.bazel

@@ -10,6 +10,7 @@ ts_library(
     ]),
     deps = [
         "//packages:types",
+        "@ngdeps//canonical-path",
         "@ngdeps//typescript",
     ],
 )

packages/compiler-cli/src/ngtsc/testing/in_memory_typescript.ts

@@ -8,7 +8,7 @@
 
 ///<reference types="jasmine"/>
 
-import * as path from 'path';
+import * as path from 'canonical-path';
 import * as ts from 'typescript';
 
 export function makeProgram(
@@ -93,7 +93,7 @@ export class InMemoryHost implements ts.CompilerHost {
   }
 
   getCanonicalFileName(fileName: string): string {
-    return path.posix.normalize(`${this.getCurrentDirectory()}/${fileName}`);
+    return path.normalize(`${this.getCurrentDirectory()}/${fileName}`);
   }
 
   useCaseSensitiveFileNames(): boolean { return true; }