Allow passing flags to cc compiler for linking

Author: xlxs4

src/JuliaC.jl

@@ -34,6 +34,7 @@ Base.@kwdef mutable struct LinkRecipe
     image_recipe::ImageRecipe = ImageRecipe()
     outname::String = ""
     rpath::Union{String, Nothing} = nothing
+    cc_flags::Vector{String} = String[]
 end
 
 Base.@kwdef mutable struct BundleRecipe

src/linking.jl

@@ -103,7 +103,11 @@ function link_products(recipe::LinkRecipe)
         mkpath(dirname(recipe.outname))
         is_shared_output = image_recipe.output_type != "--output-exe"
         # Base command
-        cmd2 = `$(compiler_cmd) $(allflags) $(rpath_str) -o $(recipe.outname)`
+        cmd2 = `$(compiler_cmd)`
+        for f in recipe.cc_flags
+            cmd2 = `$cmd2 $f`
+        end
+        cmd2 = `$cmd2 $(allflags) $(rpath_str) -o $(recipe.outname)`
         if is_shared_output
             cmd2 = `$cmd2 -shared`
         end