Define clang lld flags for hosts.

* Add -fuse-ld=lld to hostGlobalLldflags.
* Set up *ClangLldflags variables for hosts.
  They are the same as *ClangLdflags, but could be changed in the future.

Bug: 73768157
Test: make checkbuild
Change-Id: I3d61504ab7262d472bbf933df7c1a9bef62519e1
diff --git a/cc/config/x86_linux_host.go b/cc/config/x86_linux_host.go
index 6144fc2..354500e 100644
--- a/cc/config/x86_linux_host.go
+++ b/cc/config/x86_linux_host.go
@@ -78,18 +78,24 @@
 		"--sysroot ${LinuxGccRoot}/sysroot",
 	}...)
 
+	linuxClangLldflags = ClangFilterUnknownLldflags(linuxClangLdflags)
+
 	linuxX86ClangLdflags = append(ClangFilterUnknownCflags(linuxX86Ldflags), []string{
 		"-B${LinuxGccRoot}/lib/gcc/${LinuxGccTriple}/${LinuxGccVersion}/32",
 		"-L${LinuxGccRoot}/lib/gcc/${LinuxGccTriple}/${LinuxGccVersion}/32",
 		"-L${LinuxGccRoot}/${LinuxGccTriple}/lib32",
 	}...)
 
+	linuxX86ClangLldflags = ClangFilterUnknownLldflags(linuxX86ClangLdflags)
+
 	linuxX8664ClangLdflags = append(ClangFilterUnknownCflags(linuxX8664Ldflags), []string{
 		"-B${LinuxGccRoot}/lib/gcc/${LinuxGccTriple}/${LinuxGccVersion}",
 		"-L${LinuxGccRoot}/lib/gcc/${LinuxGccTriple}/${LinuxGccVersion}",
 		"-L${LinuxGccRoot}/${LinuxGccTriple}/lib64",
 	}...)
 
+	linuxX8664ClangLldflags = ClangFilterUnknownLldflags(linuxX8664ClangLdflags)
+
 	linuxClangCppflags = []string{
 		"-isystem ${LinuxGccRoot}/${LinuxGccTriple}/include/c++/${LinuxGccVersion}",
 		"-isystem ${LinuxGccRoot}/${LinuxGccTriple}/include/c++/${LinuxGccVersion}/backward",
@@ -134,6 +140,7 @@
 
 	pctx.StaticVariable("LinuxClangCflags", strings.Join(linuxClangCflags, " "))
 	pctx.StaticVariable("LinuxClangLdflags", strings.Join(linuxClangLdflags, " "))
+	pctx.StaticVariable("LinuxClangLldflags", strings.Join(linuxClangLldflags, " "))
 	pctx.StaticVariable("LinuxClangCppflags", strings.Join(linuxClangCppflags, " "))
 
 	// Extended cflags
@@ -147,7 +154,9 @@
 	pctx.StaticVariable("LinuxX8664ClangCflags",
 		strings.Join(ClangFilterUnknownCflags(linuxX8664Cflags), " "))
 	pctx.StaticVariable("LinuxX86ClangLdflags", strings.Join(linuxX86ClangLdflags, " "))
+	pctx.StaticVariable("LinuxX86ClangLldflags", strings.Join(linuxX86ClangLldflags, " "))
 	pctx.StaticVariable("LinuxX8664ClangLdflags", strings.Join(linuxX8664ClangLdflags, " "))
+	pctx.StaticVariable("LinuxX8664ClangLldflags", strings.Join(linuxX8664ClangLldflags, " "))
 	pctx.StaticVariable("LinuxX86ClangCppflags", strings.Join(linuxX86ClangCppflags, " "))
 	pctx.StaticVariable("LinuxX8664ClangCppflags", strings.Join(linuxX8664ClangCppflags, " "))
 	// Yasm flags
@@ -242,8 +251,7 @@
 }
 
 func (t *toolchainLinuxX86) ClangLldflags() string {
-	// TODO: define and use Linux*ClangLldflags
-	return "${config.LinuxClangLdflags} ${config.LinuxX86ClangLdflags}"
+	return "${config.LinuxClangLldflags} ${config.LinuxX86ClangLldflags}"
 }
 
 func (t *toolchainLinuxX8664) ClangLdflags() string {
@@ -251,8 +259,7 @@
 }
 
 func (t *toolchainLinuxX8664) ClangLldflags() string {
-	// TODO: define and use Linux*ClangLldflags
-	return "${config.LinuxClangLdflags} ${config.LinuxX8664ClangLdflags}"
+	return "${config.LinuxClangLldflags} ${config.LinuxX8664ClangLldflags}"
 }
 
 func (t *toolchainLinuxX86) YasmFlags() string {