Fix: Revert "Fix: unbound transitive dependencies should not conflict…

… with top level dependency (#4488)"

**Summary**

Fixes #4547, unfixes #3780 by reverting #4488 (commit 4020ccd).

**Test plan**

Existing unit tests.

__tests__/commands/install/integration.js

@@ -1049,7 +1049,8 @@ test.concurrent('transitive file: dependencies should work', (): Promise<void> =
   });
 });
 
-test('unbound transitive dependencies should not conflict with top level dependency', async () => {
+// Unskip once https://github.com/yarnpkg/yarn/issues/3778 is resolved
+test.skip('unbound transitive dependencies should not conflict with top level dependency', async () => {
   await runInstall({flat: true}, 'install-conflicts', async config => {
     expect((await fs.readJson(path.join(config.cwd, 'node_modules', 'left-pad', 'package.json'))).version).toEqual(
       '1.0.0',

src/package-resolver.js

@@ -228,14 +228,6 @@ export default class PackageResolver {
 
   getAllInfoForPackageName(name: string): Array<Manifest> {
     const patterns = this.patternsByPackage[name] || [];
-    return this.getAllInfoForPatterns(patterns);
-  }
-
-  /**
-   * Retrieve all the package info stored for a list of patterns.
-   */
-
-  getAllInfoForPatterns(patterns: string[]): Array<Manifest> {
     const infos = [];
     const seen = new Set();
 
@@ -292,13 +284,6 @@ export default class PackageResolver {
 
   collapseAllVersionsOfPackage(name: string, version: string): string {
     const patterns = this.dedupePatterns(this.patternsByPackage[name]);
-    return this.collapsePackageVersions(name, version, patterns);
-  }
-
-  /**
-   * Make all given patterns resolve to version.
-   */
-  collapsePackageVersions(name: string, version: string, patterns: string[]): string {
     const human = `${name}@${version}`;
 
     // get manifest that matches the version we're collapsing too
@@ -545,37 +530,10 @@ export default class PackageResolver {
       this.resolveToResolution(req);
     }
 
-    for (const dep of deps) {
-      const name = normalizePattern(dep.pattern).name;
-      this.optimizeResolutions(name);
-    }
-
     activity.end();
     this.activity = null;
   }
 
-  // for a given package, see if a single manifest can satisfy all ranges
-  optimizeResolutions(name: string) {
-    const patterns: Array<string> = this.dedupePatterns(this.patternsByPackage[name] || []);
-
-    // don't optimize things that already have a lockfile entry:
-    // https://github.com/yarnpkg/yarn/issues/79
-    const collapsablePatterns = patterns.filter(pattern => {
-      const remote = this.patterns[pattern]._remote;
-      return !this.lockfile.getLocked(pattern) && (!remote || remote.type !== 'workspace');
-    });
-    if (collapsablePatterns.length < 2) {
-      return;
-    }
-
-    const availableVersions = this.getAllInfoForPatterns(collapsablePatterns).map(manifest => manifest.version);
-    const combinedRange = collapsablePatterns.map(pattern => normalizePattern(pattern).range).join(' ');
-    const singleVersion = semver.maxSatisfying(availableVersions, combinedRange);
-    if (singleVersion) {
-      this.collapsePackageVersions(name, singleVersion, collapsablePatterns);
-    }
-  }
-
   /**
     * Called by the package requester for packages that this resolver already had
     * a matching version for. Delay the resolve, because better matches can still be