Enable f2c and complex return style autodetection on aarch64

It turns out we need these for Accelerate on apple silicon, and the
autodetection just works!  What a lovely surprise.

Author: staticfloat

src/Make.inc

@@ -80,7 +80,7 @@ endif
 # If we're on x86_64 or i686, we may need to convert back f2c-style bindings (such as Apple's Accelerate)
 # from returning doubles to instead return float's.  We enable automatic F2C detection on those platforms.
 F2C_AUTODETECTION := 0
-ifneq (,$(filter $(ARCH), x86_64 i686))
+ifneq (,$(filter $(ARCH), x86_64 i686 aarch64 arm64))
   LBT_CFLAGS += -DF2C_AUTODETECTION
   F2C_AUTODETECTION := 1
 endif
@@ -93,7 +93,7 @@ ifneq (,$(filter $(ARCH), x86_64 i686))
 endif
 
 # If we're on x86_64, we can do complex return style autodetection
-ifneq (,$(filter $(ARCH), x86_64))
+ifneq (,$(filter $(ARCH), x86_64 aarch64))
   LBT_CFLAGS += -DCOMPLEX_RETSTYLE_AUTODETECTION
   COMPLEX_RETSTYLE_AUTODETECTION := 1
 endif

test/direct.jl

@@ -47,7 +47,7 @@ lbt_handle = dlopen("$(lbt_prefix)/$(binlib)/lib$(lbt_link_name).$(shlib_ext)",
     config = lbt_get_config(lbt_handle)
 
     # If we're x86_64, ensure LBT thinks it's f2c-adapter capable
-    if Sys.ARCH == :x86_64
+    if Sys.ARCH ∈ (:x86_64, :aarch64)
         @test (config.build_flags & LBT_BUILDFLAGS_F2C_CAPABLE) != 0
     end
 
@@ -69,18 +69,22 @@ lbt_handle = dlopen("$(lbt_prefix)/$(binlib)/lib$(lbt_link_name).$(shlib_ext)",
         @test libs[1].interface == LBT_INTERFACE_LP64
     end
     @test libs[1].f2c == LBT_F2C_PLAIN
-    if Sys.ARCH == :x86_64
-        @test libs[1].cblas == LBT_CBLAS_CONFORMANT
+    if Sys.ARCH ∈ (:x86_64, :aarch64)
         if Sys.iswindows()
             @test libs[1].complex_retstyle == LBT_COMPLEX_RETSTYLE_ARGUMENT
         else
             @test libs[1].complex_retstyle == LBT_COMPLEX_RETSTYLE_NORMAL
         end
     else
-        @test libs[1].cblas == LBT_CBLAS_UNKNOWN
         @test libs[1].complex_retstyle == LBT_COMPLEX_RETSTYLE_UNKNOWN
     end
 
+    if Sys.ARCH == :x86_64
+        @test libs[1].cblas == LBT_CBLAS_CONFORMANT
+    else
+        @test libs[1].cblas == LBT_CBLAS_UNKNOWN
+    end
+
     @test bitfield_get(libs[1].active_forwards, dgemm_idx) != 0
 
     # Next check OpenBLAS32_jll which is always LP64