Re-enable -Wno-defaulted-function-deleted warnings.

LLVM was updated to the latest 7.0.1 revision, which includes the proper
fix.

Reverts "Fixed build on Arm 64"
This reverts commit fed67899a7b44c9409e94442eaca0deab2f809e3.

Bug b/123026156
Bug chromium:922089

Change-Id: I1f6ee4d3869e642e6ce2bd8cbf2c8f7553e4a607
Reviewed-on: https://swiftshader-review.googlesource.com/c/24150
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/Reactor/BUILD.gn

diff --git a/src/Reactor/BUILD.gn b/src/Reactor/BUILD.gn
index be5e505..c983c43 100644
--- a/src/Reactor/BUILD.gn
+++ b/src/Reactor/BUILD.gn
@@ -170,9 +170,6 @@
     ]
   } else {
     cflags = [ "-Wno-unused-local-typedef" ]
-    if(target_cpu == "arm64") {

-      cflags += [ "-Wno-defaulted-function-deleted" ]

-    }

     defines = [
       "__STDC_CONSTANT_MACROS",
       "__STDC_LIMIT_MACROS",

third_party/llvm-7.0/BUILD.gn

diff --git a/third_party/llvm-7.0/BUILD.gn b/third_party/llvm-7.0/BUILD.gn
index f0b3dc8..4ccc6d1 100644
--- a/third_party/llvm-7.0/BUILD.gn
+++ b/third_party/llvm-7.0/BUILD.gn
@@ -61,10 +61,6 @@
     }
   }
 
-  if(target_cpu == "arm64") {

-    cflags += [ "-Wno-defaulted-function-deleted" ]

-  }

-

   cflags += [
     "-Wno-attributes",
     "-Wno-deprecated-declarations",