Support all Windows paths

[jridgewell]

@cspotcode: Please try this branch to see if it resolves your issues.

Fixes #108.

[cspotcode]

Thanks, I appreciate it. I got to a point where tests are passing with the workaround I implemented, and I want to move on to some other things, so it might be a bit before I'm able to test this.

[liuxingbaoyu]

Hi! Can you merge this PR? I tried to fix babel/babel#15784 based on this.

diff --git a/src/resolve-uri.ts b/src/resolve-uri.ts
index 1a52169..dc952ea 100644
--- a/src/resolve-uri.ts
+++ b/src/resolve-uri.ts
@@ -294,6 +294,7 @@ export default function resolve(input: string, base: string | undefined): string
   const inputIsWindows = isWindowsPath(input);
   const baseIsWindows = !inputIsWindows && !!base && isWindowsPath(base);
   if (!inputIsWindows && !baseIsWindows) return resolveInternal(input, base || '');
+  if (!inputIsWindows && baseIsWindows) input = toWindows(input);
 
   const resolved = resolveInternal(windowsToUrl(input), windowsToUrl(base || ''));
   return toWindows(resolved);
diff --git a/test/with-absolute-Windows-path-base.test.js b/test/with-absolute-Windows-path-base.test.js
index 074dd17..623022d 100644
--- a/test/with-absolute-Windows-path-base.test.js
+++ b/test/with-absolute-Windows-path-base.test.js
@@ -1776,6 +1776,20 @@ describe('with absolute Windows path base', () => {
         const resolved = resolve(input, base);
         assert.strictEqual(resolved, 'C:\\main.js.map');
       });
+
+      it('normalizes mixed `/` and `\\` #babel/15784', () => {
+        const base = 'C:\\root\\dir\\';
+        const input = 'C:/root/dir/main.js.map';
+        const resolved = resolve(input, base);
+        assert.strictEqual(resolved, 'C:\\root\\dir\\main.js.map');
+      });
+
+      it('normalizes mixed `/` and `\\` 2', () => {
+        const base = 'C:/root/dir/\\';
+        const input = 'C:\\root\\dir\\main.js.map';
+        const resolved = resolve(input, base);
+        assert.strictEqual(resolved, 'C:\\root\\dir\\main.js.map');
+      });
     });
 
     describe('with leading dot relative input', () => {