Initialize GC bitmaps for manually defined builtins

We err on the safe side by initializing the GC bitmaps to all 1s which
means they will be scanned in their entirety.

Author: plajjan

builtin/src/__builtin__.ext.c

@@ -0,0 +1,21 @@
+
+void B___ext_init__() {
+    memset(B_boolD_gcbm, 0xFF, sizeof(B_boolD_gcbm));
+    memset(B_complexD_gcbm, 0xFF, sizeof(B_complexD_gcbm));
+    memset(B_dictD_gcbm, 0xFF, sizeof(B_dictD_gcbm));
+    memset(B_floatD_gcbm, 0xFF, sizeof(B_floatD_gcbm));
+    memset(B_i16D_gcbm, 0xFF, sizeof(B_i16D_gcbm));
+    memset(B_i32D_gcbm, 0xFF, sizeof(B_i32D_gcbm));
+    memset(B_i64D_gcbm, 0xFF, sizeof(B_i64D_gcbm));
+    memset(B_intD_gcbm, 0xFF, sizeof(B_intD_gcbm));
+    memset(B_listD_gcbm, 0xFF, sizeof(B_listD_gcbm));
+    memset(B_rangeD_gcbm, 0xFF, sizeof(B_rangeD_gcbm));
+    memset(B_setD_gcbm, 0xFF, sizeof(B_setD_gcbm));
+    memset(B_sliceD_gcbm, 0xFF, sizeof(B_sliceD_gcbm));
+    memset(B_strD_gcbm, 0xFF, sizeof(B_strD_gcbm));
+    memset(B_bytearrayD_gcbm, 0xFF, sizeof(B_bytearrayD_gcbm));
+    memset(B_bytesD_gcbm, 0xFF, sizeof(B_bytesD_gcbm));
+    memset(B_u16D_gcbm, 0xFF, sizeof(B_u16D_gcbm));
+    memset(B_u32D_gcbm, 0xFF, sizeof(B_u32D_gcbm));
+    memset(B_u64D_gcbm, 0xFF, sizeof(B_u64D_gcbm));
+}

compiler/Acton/CodeGen.hs

@@ -310,8 +310,8 @@ cModule env srcbase (Module m imps stmts)
                                       if inBuiltin env then empty else char '}'   -- Temporary fix until __builtin__ADD.c not necessary
   where initImports                 = vcat [ gen env (GName m initKW) <> parens empty <> semi | m <- modNames imps ]
         external                    = hasNotImpl stmts && not (inBuiltin env)
-        ext_include                 = if external then text "#include" <+> doubleQuotes (text srcbase <> text ".ext.c") else empty
-        ext_init                    = if external then genTopName env (name "__ext_init__") <+> parens empty <> semi else empty
+        ext_include                 = if hasNotImpl stmts then text "#include" <+> doubleQuotes (text srcbase <> text ".ext.c") else empty
+        ext_init                    = if hasNotImpl stmts then genTopName env (name "__ext_init__") <+> parens empty <> semi else empty
 
 
 declModule env []                   = empty