Revert r211866, r211895 and r211995, "Driver: use GNU::Link for the Generic_GCC toolchain". It broke users of Generic_GCC, cygwin and mingw32.

It reverts commits as follows:
  r211866: "Driver: use GNU::Link for the Generic_GCC toolchain"
  r211895: "Replace GetProgramPath("ld") with GetLinkerPath()."
  r211995: "Driver: add a cygwin linker tool"

llvm-svn: 211998
diff --git a/clang/test/Driver/bindings.c b/clang/test/Driver/bindings.c
index 9653a57..dd8ad14 100644
--- a/clang/test/Driver/bindings.c
+++ b/clang/test/Driver/bindings.c
@@ -2,7 +2,7 @@
 // RUN: %clang -target i386-unknown-unknown -ccc-print-bindings -no-integrated-as %s 2>&1 | FileCheck %s --check-prefix=CHECK01
 // CHECK01: "clang", inputs: ["{{.*}}bindings.c"], output: "{{.*}}.s"
 // CHECK01: "GNU::Assemble", inputs: ["{{.*}}.s"], output: "{{.*}}.o"
-// CHECK01: "GNU::Link", inputs: ["{{.*}}.o"], output: "a.out"
+// CHECK01: "gcc::Link", inputs: ["{{.*}}.o"], output: "a.out"
 
 // Clang control options