Migrated GN target :isac_fix_test

Migrated GN target :isac_fix_test from
webrtc/modules/audio_coding/codecs/isac/isacfix_test.gypi

NOTRY=True

BUG=webrtc:6191

Review-Url: https://codereview.webrtc.org/2247233002
Cr-Commit-Position: refs/heads/master@{#13770}
diff --git a/.gn b/.gn
index e151f7c..841989c 100644
--- a/.gn
+++ b/.gn
@@ -19,7 +19,10 @@
 # their includes checked for proper dependencies when you run either
 # "gn check" or "gn gen --check".
 # TODO(kjellander): Keep adding paths to this list as work in webrtc:5589 is done.
-check_targets = [ "//webrtc/voice_engine:level_indicator" ]
+check_targets = [
+  "//webrtc/voice_engine:level_indicator",
+  "//webrtc/modules/audio_coding:isac_fix_test",
+]
 
 # These are the list of GN files that run exec_script. This whitelist exists
 # to force additional review for new uses of exec_script, which is strongly
diff --git a/webrtc/modules/audio_coding/BUILD.gn b/webrtc/modules/audio_coding/BUILD.gn
index 512f042..2f28ccc 100644
--- a/webrtc/modules/audio_coding/BUILD.gn
+++ b/webrtc/modules/audio_coding/BUILD.gn
@@ -1483,4 +1483,24 @@
       "//third_party/gflags",
     ]
   }
+
+  executable("isac_fix_test") {
+    testonly = true
+
+    sources = [
+      "codecs/isac/fix/test/kenny.cc",
+    ]
+
+    deps = [
+      ":isac_fix",
+      "../../test:test_support",
+    ]
+
+    if (is_win) {
+      cflags = [
+        # Disable warnings to enable Win64 build, issue 1323.
+        "/wd4267",  # size_t to int truncation
+      ]
+    }
+  }
 }