build: fix source-map warnings for ts-api-guardian

* Fixes that running `ts-api-guardian` targets always causes source map warnings to appear.

tools/ts-api-guardian/package.json

@@ -26,6 +26,7 @@
     "@types/node": "^10.9.2",
     "chai": "^4.1.2",
     "jasmine": "^3.1.0",
+    "source-map-support": "^0.5.9",
     "typescript": "~3.1.1"
   },
   "repository": {},

tools/ts-api-guardian/yarn.lock

@@ -52,6 +52,11 @@ brace-expansion@^1.1.7:
     balanced-match "^1.0.0"
     concat-map "0.0.1"
 
+buffer-from@^1.0.0:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/buffer-from/-/buffer-from-1.1.1.tgz#32713bc028f75c02fdb710d7c7bcec1f2c6070ef"
+  integrity sha512-MQcXEUbCKtEo7bhqEs6560Hyd4XaovZlO/k9V3hjVUF/zwW7KBVdSK4gIt/bzwS9MbR5qob+F5jusZsb0YQK2A==
+
 chai@^4.1.2:
   version "4.1.2"
   resolved "https://registry.yarnpkg.com/chai/-/chai-4.1.2.tgz#0f64584ba642f0f2ace2806279f4f06ca23ad73c"
@@ -194,6 +199,19 @@ pathval@^1.0.0:
   resolved "https://registry.yarnpkg.com/pathval/-/pathval-1.1.0.tgz#b942e6d4bde653005ef6b71361def8727d0645e0"
   integrity sha1-uULm1L3mUwBe9rcTYd74cn0GReA=
 
+source-map-support@^0.5.9:
+  version "0.5.9"
+  resolved "https://registry.yarnpkg.com/source-map-support/-/source-map-support-0.5.9.tgz#41bc953b2534267ea2d605bccfa7bfa3111ced5f"
+  integrity sha512-gR6Rw4MvUlYy83vP0vxoVNzM6t8MUXqNuRsuBmBHQDu1Fh6X015FrLdgoDKcNdkwGubozq0P4N0Q37UyFVr1EA==
+  dependencies:
+    buffer-from "^1.0.0"
+    source-map "^0.6.0"
+
+source-map@^0.6.0:
+  version "0.6.1"
+  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
+  integrity sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==
+
 supports-color@^5.3.0:
   version "5.3.0"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-5.3.0.tgz#5b24ac15db80fa927cf5227a4a33fd3c4c7676c0"