fix(build): reactivate optimisations and llvm backend

package.yaml

@@ -255,14 +255,12 @@ ghc-options:
   - -fno-warn-partial-type-signatures
   - -fno-max-relevant-binds
   - -j
-  - -freduction-depth=0
-  - +RTS -K0 -RTS
+  - -freduction-depth=0  
 when:
   - condition: flag(pedantic)
     ghc-options:
       - -Werror
-      - -fwarn-tabs
-      - -O0
+      - -fwarn-tabs      
   - condition: flag(dev)
     then:
       ghc-options:
@@ -273,7 +271,9 @@ when:
       cpp-options: -DDEVELOPMENT
     else:
       ghc-options:
-        - -O0
+        - -O
+        - -fllvm
+        - +RTS -K0 -RTS
 data-files:
   - testdata/**
 library: