"Go to references" errors when there are no references

[harrisont]

Repro

Attempt to "go to references" of the 1 in:

.A = 1

Expected behavior

No references

Actual behavior

Getting references fails:

[Trace - 6:36:33 PM] Sending request 'textDocument/references - (34)'.
[Trace - 6:36:33 PM] Received response 'textDocument/references - (34)' in 60ms. Request failed: Request textDocument/references failed with message: Reduce of empty array with no initial value (-32603).
[Error - 6:36:33 PM] Request textDocument/references failed.
  Message: Request textDocument/references failed with message: Reduce of empty array with no initial value
  Code: -32603 

Internally, the error is:

TypeError: Reduce of empty array with no initial value
 at Array.reduce (<anonymous>)
 at getVariableReferences (server\src\features\referenceProvider.ts:94:10)
 at Object.getReferences (server\src\features\referenceProvider.ts:34:24)