Enable lld for windows

Bug: http://b/110800681

The following flags that the binutils linkers support are not available
in lld for Windows:
  -soname
  --no-undefined
  -rpath

Windows also uses "import libraries", which are stub libraries used only
for linking.  The binutils linkers accepted a DLL and treated them as an
import library.  But lld issues the following error:

  lld-link: error: ...DLL: bad file type. Did you specify a DLL instead
  of an import library?

To resolve this, pass '-out-implib=libFoo.a' to lld when linking
libFoo.dll.  Add libFoo.a as an implicit output to the 'ld' build rule.

Rewrite the shared libraries for a library/binary to use the import
library instead of the DLL.  As a side-effect, this also (correctly)
uses the AdbWinApi.a that's alongside
development/host/windows/prebuilt/usb/AdbWinApi.dll

Test: Run Windows tests (go/android-llvm-windows-testing) and check
absence of regressions.

Change-Id: I15a178589aa6882caa6e7e38650cc6ef48109764
diff --git a/cc/builder.go b/cc/builder.go
index 97ae806..dab887c 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -26,6 +26,7 @@
 	"strings"
 
 	"github.com/google/blueprint"
+	"github.com/google/blueprint/pathtools"
 
 	"android/soong/android"
 	"android/soong/cc/config"
@@ -597,7 +598,7 @@
 // and shared libraries, to a shared library (.so) or dynamic executable
 func TransformObjToDynamicBinary(ctx android.ModuleContext,
 	objFiles, sharedLibs, staticLibs, lateStaticLibs, wholeStaticLibs, deps android.Paths,
-	crtBegin, crtEnd android.OptionalPath, groupLate bool, flags builderFlags, outputFile android.WritablePath) {
+	crtBegin, crtEnd android.OptionalPath, groupLate bool, flags builderFlags, outputFile android.WritablePath, implicitOutputs android.WritablePaths) {
 
 	ldCmd := "${config.ClangBin}/clang++"
 
@@ -634,7 +635,11 @@
 	}
 
 	for _, lib := range sharedLibs {
-		libFlagsList = append(libFlagsList, lib.String())
+		libFile := lib.String()
+		if ctx.Windows() {
+			libFile = pathtools.ReplaceExtension(libFile, "a")
+		}
+		libFlagsList = append(libFlagsList, libFile)
 	}
 
 	deps = append(deps, staticLibs...)
@@ -645,11 +650,12 @@
 	}
 
 	ctx.Build(pctx, android.BuildParams{
-		Rule:        ld,
-		Description: "link " + outputFile.Base(),
-		Output:      outputFile,
-		Inputs:      objFiles,
-		Implicits:   deps,
+		Rule:            ld,
+		Description:     "link " + outputFile.Base(),
+		Output:          outputFile,
+		ImplicitOutputs: implicitOutputs,
+		Inputs:          objFiles,
+		Implicits:       deps,
 		Args: map[string]string{
 			"ldCmd":    ldCmd,
 			"crtBegin": crtBegin.String(),