Normalize paths when looking up items on outputCache

[cspotcode]

Fixes #1037

• add regression test. Intentionally throw an error, assert that the line number is correct

[coveralls]

Coverage remained the same at 81.137% when pulling f588826 on ab/fix-source-maps-on-windows into 2397f3a on master.

[cspotcode]

The failures look like a mistake in how I set up the CI stuff. I need to mark those Coveralls - run-* executions as not affecting the CI success/failure.

[cspotcode]

Results of manual, local test, using the reproduction from #1037. Line number is correct.

Since our build script spits out a tarball now, this made it easy to switch from Linux to Windows, install the tarball, and test.

D:\Personal-dev\@TypeStrong\ts-node-repros\1037>npm install ..\..\ts-node\tests\ts-node-packed.tgz npm WARN 1037 No repository field. npm WARN 1037 No license field. + ts-node@8.10.1 updated 1 package and audited 9 packages in 1.053s found 0 vulnerabilities D:\Personal-dev\@TypeStrong\ts-node-repros\1037>.\node_modules\.bin\ts-node.cmd .\example.ts D:\Personal-dev\@TypeStrong\ts-node-repros\1037\example.ts:8 throw new Error("aaa") ^ Error: aaa at main (D:\Personal-dev\@TypeStrong\ts-node-repros\1037\example.ts:8:11) at Object.<anonymous> (D:\Personal-dev\@TypeStrong\ts-node-repros\1037\example.ts:17:3) at Module._compile (internal/modules/cjs/loader.js:1185:30) at Module.m._compile (D:\Personal-dev\@TypeStrong\ts-node-repros\1037\node_modules\ts-node\src\index.ts:858:23) at Module._extensions..js (internal/modules/cjs/loader.js:1205:10) at Object.require.extensions.<computed> [as .ts] (D:\Personal-dev\@TypeStrong\ts-node-repros\1037\node_modules\ts-node\src\index.ts:861:12) at Module.load (internal/modules/cjs/loader.js:1034:32) at Function.Module._load (internal/modules/cjs/loader.js:923:14) at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12) at main (D:\Personal-dev\@TypeStrong\ts-node-repros\1037\node_modules\ts-node\src\bin.ts:227:14) D:\Personal-dev\@TypeStrong\ts-node-repros\1037> 

[cspotcode]

I wasn't 100% sure that the sourcemap tests were proving that line numbers are correct. So I added a silly amount of whitespace to be sure.