add warning bools test

Author: zlonast

cabal-testsuite/PackageTests/ProjectConfig/FlagsBools/cabal.out

@@ -0,0 +1,8 @@
+# cabal build
+Resolving dependencies...
+Build profile: -w ghc-<GHCVER> -O1
+In order, the following will be built:
+ - test-0.1 (lib) (first run)
+Configuring library for test-0.1...
+Preprocessing library for test-0.1...
+Building library for test-0.1...

cabal-testsuite/PackageTests/ProjectConfig/FlagsBools/cabal.project

@@ -0,0 +1,8 @@
+packages: .
+
+build-info: true
+optimization: tRuE
+
+package test
+  flags: -bar
+  flags: -baz

cabal-testsuite/PackageTests/ProjectConfig/FlagsBools/cabal.test.hs

@@ -0,0 +1,4 @@
+import Test.Cabal.Prelude
+
+main = cabalTest $ do
+  cabal "build" []

cabal-testsuite/PackageTests/ProjectConfig/FlagsBools/test.cabal

@@ -0,0 +1,26 @@
+cabal-version:  3.0
+name:           test
+version:        0.1
+license:        BSD-3-Clause
+build-type:     Simple
+
+flag bar
+  default: true
+  manual: True
+
+flag baz
+  default: TRUE
+  manual: True
+
+flag quux
+  default: false
+  manual: False
+
+flag quuux
+  default: FALSE
+  manual: false
+
+Library
+  default-language: Haskell2010
+  if flag(bar) || flag (baz)
+    buildable: false