Add patch for undefined __acrt_iob_func issue (#870)

Author: hamishmack

overlays/bootstrap.nix

@@ -135,6 +135,8 @@ in {
                 ++ final.lib.optional (versionAtLeast "8.6.4" && versionLessThan "8.8") ./patches/ghc/ghc-no-system-linker.patch
 
                 ++ fromUntil "8.10.2" "8.12"   ./patches/ghc/MR3714-backported-to-8.10.2.patch
+
+                ++ from      "8.10.1"          ./patches/ghc/ghc-acrt-iob-func.patch
                 ;
         in ({
             ghc844 = final.callPackage ../compiler/ghc {

overlays/patches/ghc/ghc-acrt-iob-func.patch

@@ -0,0 +1,12 @@
+diff --git a/rts/RtsSymbols.c b/rts/RtsSymbols.c
+index b2f90a892d..c552652247 100644
+--- a/rts/RtsSymbols.c
++++ b/rts/RtsSymbols.c
+@@ -140,6 +140,7 @@
+       RTS_WIN64_ONLY(SymI_HasProto(__imp__environ))      \
+       RTS_WIN32_ONLY(SymI_HasProto(_imp___iob))          \
+       RTS_WIN64_ONLY(SymI_HasProto(__iob_func))          \
++      RTS_WIN64_ONLY(SymI_HasProto(__acrt_iob_func))     \
+       /* see Note [Symbols for MinGW's printf] */        \
+       SymI_HasProto(_lock_file)                          \
+       SymI_HasProto(_unlock_file)                        \