Do not process library reference directives with noLib set.

When a user sets `noLib`, this indicates that they will supply their own
list of `lib*.d.ts` files as part of input sources. In this situation,
TypeScript should not try to resolve library reference directives.

This avoids a problem where TypeScript loads a file that e.g. contains
`/// <reference lib="es2015.symbol"/>`. Previously, TypeScript would use
its builtin ts.libMap and attempt to load builtin libraries from the
TypeScript installation, instead of respecting the user-supplied set of
libraries.

Author: mprobst

src/compiler/program.ts

@@ -2227,8 +2227,9 @@ namespace ts {
                         processReferencedFiles(file, isDefaultLib);
                         processTypeReferenceDirectives(file);
                     }
-
-                    processLibReferenceDirectives(file);
+                    if (!options.noLib) {
+                        processLibReferenceDirectives(file);
+                    }
 
                     modulesWithElidedImports.set(file.path, false);
                     processImportedModules(file);
@@ -2315,8 +2316,10 @@ namespace ts {
                     processReferencedFiles(file, isDefaultLib);
                     processTypeReferenceDirectives(file);
                 }
+                if (!options.noLib) {
+                    processLibReferenceDirectives(file);
+                }
 
-                processLibReferenceDirectives(file);
 
                 // always process imported modules to record module name resolutions
                 processImportedModules(file);