Check trace enabled befoe tracing

Author: mhegazy

src/compiler/moduleNameResolver.ts

@@ -1,4 +1,4 @@
-/// <reference path="core.ts" />
+/// <reference path="core.ts" />
 /// <reference path="diagnosticInformationMap.generated.ts" />
 
 namespace ts {
@@ -824,7 +824,9 @@ namespace ts {
                     if (resolved) {
                         return resolved;
                     }
-                    trace(state.host, Diagnostics.File_0_has_an_unsupported_extension_so_skipping_it, fromExactFile);
+                    if (state.traceEnabled) {
+                        trace(state.host, Diagnostics.File_0_has_an_unsupported_extension_so_skipping_it, fromExactFile);
+                    }
                 }
                 const resolved = tryAddingExtensions(mainOrTypesFile, Extensions.TypeScript, failedLookupLocations, onlyRecordFailures, state);
                 if (resolved) {