Tests: add tests where package has multiple products with same name

Add tests to ensure SwiftPM support products with same name, but with
different case sensitivity.

relates to #9184
Issue: rdar://161264250

Author: bkhouri

Fixtures/MyltipleProductsHaveSameNameButDifferentCaseSensitivity/Package.swift

@@ -0,0 +1,48 @@
+// swift-tools-version: 6.1
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "TwoProductsHaveSameNameButDifferentCaseSensitivity",
+    products: [
+        .library(
+            name: "MyProduct",
+            targets: [
+                "MyProduct",
+            ],
+        ),
+        .executable(
+            name: "myproduct",
+            targets: [
+                "execTargetNoMainFunction",
+            ],
+        ),
+        .executable(
+            name: "myProduct",
+            targets: [
+                "execTargetWithAtMain",
+            ],
+        ),
+        .executable(
+            name: "Myproduct",
+            targets: [
+                "execTargetNoAtMainButHasMainDotSwift",
+            ],
+        ),
+    ],
+    targets: [
+        .target(
+            name: "MyProduct",
+        ),
+        .executableTarget(
+            name: "execTargetNoMainFunction",
+        ),
+        .executableTarget(
+            name: "execTargetWithAtMain"
+        ),
+        .executableTarget(
+            name: "execTargetNoAtMainButHasMainDotSwift"
+        ),
+    ],
+)

Fixtures/MyltipleProductsHaveSameNameButDifferentCaseSensitivity/Sources/MyProduct/lib1.swift

@@ -0,0 +1,6 @@
+
+func main() {
+    print("Hello, world with main function")
+}
+
+main()

Fixtures/MyltipleProductsHaveSameNameButDifferentCaseSensitivity/Sources/execTargetNoAtMainButHasMainDotSwift/main.swift

@@ -0,0 +1,2 @@
+
+print("Hello, world. with main.swift inline as a script")

Fixtures/MyltipleProductsHaveSameNameButDifferentCaseSensitivity/Sources/execTargetNoMainFunction/main.swift

@@ -0,0 +1,7 @@
+
+@main
+struct ExecTargetWithAtMainMain {
+    static func main() {
+        print("Hello, world with @main")
+    }
+}

Fixtures/MyltipleProductsHaveSameNameButDifferentCaseSensitivity/Sources/execTargetWithAtMain/execTargetWithAtMain.swift

@@ -24,7 +24,6 @@ import enum PackageModel.BuildConfiguration
 import class Basics.AsyncProcess
 
 @Suite(
-    .serialized, // to limit the number of swift executable running.
     .tags(
         Tag.TestSize.large,
         Tag.Feature.Command.Run,
@@ -135,6 +134,40 @@ struct RunCommandTests {
         }
     }
 
+    @Test(
+        arguments: SupportedBuildSystemOnAllPlatforms, [
+            (
+                fixtureNameUT: "MyltipleProductsHaveSameNameButDifferentCaseSensitivity",
+                productUT: "myproduct",
+                expectedOutput: "Hello, world. with main.swift inline as a script",
+            ),
+            (
+                fixtureNameUT: "MyltipleProductsHaveSameNameButDifferentCaseSensitivity",
+                productUT: "myProduct",
+                expectedOutput: "Hello, world with @main",
+            ),
+            (
+                fixtureNameUT: "MyltipleProductsHaveSameNameButDifferentCaseSensitivity",
+                productUT: "Myproduct",
+                expectedOutput: "Hello, world with main function",
+            ),
+        ],
+    )
+    func testPackageHasMultipleProductsWithSameNameButDifferentCaseSensitivity(
+        buildSystem: BuildSystemProvider.Kind,
+        data: (fixtureNameUT: String, productUT: String, expectedOutput: String),
+    ) async throws {
+        try await fixture(name: data.fixtureNameUT) { fixturePath in
+            let (stdout, _) = try await executeSwiftRun(
+                fixturePath,
+                data.productUT,
+                buildSystem: buildSystem,
+            )
+
+            #expect(stdout.contains(data.expectedOutput))
+        }
+    }
+
     @Test(
          .tags(
             .Feature.TargetType.Executable,