Add install by copy test and skip symlink install for Windows

cabal-testsuite/PackageTests/WarnEarlyOverwrite/clean-install-by-copy.out

@@ -0,0 +1,12 @@
+# cabal v2-install
+Wrote tarball sdist to <ROOT>/clean-install-by-copy.dist/work/./dist/sdist/WarnEarlyOverwrite-0.1.0.0.tar.gz
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - WarnEarlyOverwrite-0.1.0.0 (exe:warn-early-overwrite) (requires build)
+Configuring executable 'warn-early-overwrite' for WarnEarlyOverwrite-0.1.0.0...
+Preprocessing executable 'warn-early-overwrite' for WarnEarlyOverwrite-0.1.0.0...
+Building executable 'warn-early-overwrite' for WarnEarlyOverwrite-0.1.0.0...
+Installing executable warn-early-overwrite in <PATH>
+Warning: The directory <GBLTMPDIR>/ghc-<GHCVER>/incoming/new-<RAND><GBLTMPDIR>/ghc-<GHCVER>/<PACKAGE>-<HASH>/bin is not in the system search path.
+Copying 'warn-early-overwrite' to '<GBLTMPDIR>/warn-early-overwrite'

cabal-testsuite/PackageTests/WarnEarlyOverwrite/clean-install-by-copy.test.hs

@@ -0,0 +1,6 @@
+import Test.Cabal.Prelude
+
+main = withShorterPathForNewBuildStore $ \storeDir -> cabalTest $ do
+    let options = ["--store-dir=" ++ storeDir, "--installdir=" ++ storeDir]
+    -- Use install method copy that should surely work on Windows too.
+    cabalG options "v2-install" ["--install-method=copy"]

cabal-testsuite/PackageTests/WarnEarlyOverwrite/clean-install.out → cabal-testsuite/PackageTests/WarnEarlyOverwrite/clean-install-by-symlink.out

@@ -1,5 +1,5 @@
 # cabal v2-install
-Wrote tarball sdist to <ROOT>/clean-install.dist/work/./dist/sdist/WarnEarlyOverwrite-0.1.0.0.tar.gz
+Wrote tarball sdist to <ROOT>/clean-install-by-symlink.dist/work/./dist/sdist/WarnEarlyOverwrite-0.1.0.0.tar.gz
 Resolving dependencies...
 Build profile: -w ghc-<GHCVER> -O1
 In order, the following will be built:

cabal-testsuite/PackageTests/WarnEarlyOverwrite/clean-install.test.hs → cabal-testsuite/PackageTests/WarnEarlyOverwrite/clean-install-by-symlink.test.hs

@@ -1,7 +1,7 @@
 import Test.Cabal.Prelude
 
 main = withShorterPathForNewBuildStore $ \storeDir -> cabalTest $ do
-    -- The default install method is symlink, which may not work on Windows.
+    -- The default install method is symlink that may not work on Windows.
     skipIfWindows
     let options = ["--store-dir=" ++ storeDir, "--installdir=" ++ storeDir]
     cabalG options "v2-install" []