hadrian: re-enable PIC for gmp on wasm

This commit re-enables --with-pic=yes configuration option of gmp when
building for wasm, given we're about to include support for shared
libraries, TH and ghci.

(cherry picked from commit 775410fd)

hadrian/src/Settings/Builders/Configure.hs

@@ -28,10 +28,7 @@ configureBuilderArgs = do
                      -- more detailed explanation of this configure
                      -- option.
                      <> [ "--enable-alloca=malloc-notreentrant" | targetArch == "wasm32" ]
-                     -- Enable PIC unless target is wasm32, in which
-                     -- case we don't want libgmp.a to be bloated due
-                     -- to PIC overhead.
-                     <> [ "--with-pic=yes" | targetArch /= "wasm32" ]
+                     <> [ "--with-pic=yes" ]
 
             , builder (Configure libffiPath) ? do
                 top            <- expr topDirectory