profile: ignore WayDyn in profileBuildTag for unified interface files

With -dynamic-too deprecated and all .hi/.o files unified, WayDyn no
longer affects the ABI of interface or object files. The profile build
tag (used for interface file compatibility checks in Iface/Binary.hs)
must not include the "dyn" component, otherwise we get:

    mismatched interface file profile tag (wanted "dyn", got "")

This occurs when Cabal builds packages with --enable-shared (-dynamic)
using a stage2 compiler whose libraries were compiled without -dynamic.
The .hi files have tag "" but the reader expects "dyn".

By filtering WayDyn from the ways before computing waysBuildTag, both
the writing and reading sides produce consistent tags regardless of
whether -dynamic is passed. This follows the same pattern as the Finder
and Linker fixes (commits 59cc152, 8a64142).

Author: angerman

compiler/GHC/Platform/Profile.hs

@@ -50,4 +50,8 @@ profileBuildTag profile
   | otherwise                       =     wayTag
   where
    platform = profilePlatform profile
-   wayTag   = waysBuildTag (profileWays profile)
+   -- Ignore WayDyn: since -dynamic-too is deprecated, all .hi and .o files
+   -- are unified (no separate .dyn_hi / .dyn_o). WayDyn no longer affects
+   -- the ABI of interface or object files, so it must not contribute to the
+   -- build tag used for interface file compatibility checks.
+   wayTag   = waysBuildTag (removeWay WayDyn (profileWays profile))