src/pathUtils: check /usr/local/bin/go for go

This is a frequently used installation path for
custom executables including go in newer mac, but
this isn't included in system default PATH.
Many users add this in their login shell, or
/etc/paths.d, but when VSCode fails to load the
environment, the users end up with the incomplete
PATH, and go couldn't be found. Since this problem
got worsened recently, add /usr/local/bin/go to
the fallback path list.

For golang/vscode-go#971

Change-Id: Ie635b58c835189fbf1523c71cf4b6bac5e8400e3
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/276493
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>
Trust: Suzy Mueller <suzmue@golang.org>
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/src/utils/pathUtils.ts b/src/utils/pathUtils.ts
index 0b93650..235ca8b 100644
--- a/src/utils/pathUtils.ts
+++ b/src/utils/pathUtils.ts
@@ -98,12 +98,14 @@
 		return {binPath: pathFromPath, why: found('path')};
 	}
 
-	// Check default path for go
+	// Check common paths for go
 	if (toolName === 'go') {
-		const defaultPathForGo = process.platform === 'win32' ? 'C:\\Go\\bin\\go.exe' : '/usr/local/go/bin/go';
-		if (executableFileExists(defaultPathForGo)) {
-			binPathCache[toolName] = defaultPathForGo;
-			return {binPath: defaultPathForGo, why: 'default'};
+		const defaultPathsForGo = process.platform === 'win32' ? ['C:\\Go\\bin\\go.exe'] : ['/usr/local/go/bin/go', '/usr/local/bin/go'];
+		for (const p of defaultPathsForGo) {
+			if (executableFileExists(p)) {
+				binPathCache[toolName] = p;
+			}
+			return {binPath: p, why: 'default'};
 		}
 		return {binPath: ''};
 	}