Fix NaCl build.

Apparently I enabled the queries for NaCl without testing at all.

src/Magnum/AbstractObject.cpp

@@ -83,8 +83,13 @@ namespace {
             /**
              * @todo Shouldn't ES2's KHR_debug have `GL_TRANSFORM_FEEDBACK_KHR`
              *      instead of `GL_TRANSFORM_FEEDBACK`? (it's a new enum in 2.0)
+             *      NaCl extension header doesn't have it at all. Also the
+             *      original @es_extension{EXT,debug_label} mentions it only
+             *      for ES3 (i.e. no mention of @es_extension{EXT,transform_feedback})
              */
+            #ifndef CORRADE_TARGET_NACL
             case GL_TRANSFORM_FEEDBACK:
+            #endif
             #ifndef MAGNUM_TARGET_GLES
             case GL_SAMPLER:
             #else

src/Magnum/Query.cpp

@@ -82,7 +82,7 @@ bool AbstractQuery::resultAvailable() {
     #ifndef MAGNUM_TARGET_GLES2
     glGetQueryObjectuiv(_id, GL_QUERY_RESULT_AVAILABLE, &result);
     #elif defined(CORRADE_TARGET_NACL)
-    glGetQueryObjectuivEXT(_id, GL_QUERY_RESULT_AVAILABLE, &result);
+    glGetQueryObjectuivEXT(_id, GL_QUERY_RESULT_AVAILABLE_EXT, &result);
     #else
     CORRADE_INTERNAL_ASSERT(false);
     #endif
@@ -98,7 +98,7 @@ template<> UnsignedInt AbstractQuery::result<UnsignedInt>() {
     #ifndef MAGNUM_TARGET_GLES2
     glGetQueryObjectuiv(_id, GL_QUERY_RESULT, &result);
     #elif defined(CORRADE_TARGET_NACL)
-    glGetQueryObjectuivEXT(_id, GL_QUERY_RESULT, &result);
+    glGetQueryObjectuivEXT(_id, GL_QUERY_RESULT_EXT, &result);
     #else
     CORRADE_INTERNAL_ASSERT(false);
     #endif
@@ -115,7 +115,7 @@ template<> Int AbstractQuery::result<Int>() {
     #ifndef MAGNUM_TARGET_GLES
     glGetQueryObjectiv(_id, GL_QUERY_RESULT, &result);
     #elif defined(CORRADE_TARGET_NACL)
-    glGetQueryObjectivEXT(_id, GL_QUERY_RESULT, &result);
+    glGetQueryObjectivEXT(_id, GL_QUERY_RESULT_EXT, &result);
     #else
     CORRADE_INTERNAL_ASSERT(false);
     #endif