Remove clang indirection without affecting build.ninja

Remove cflags that are not handled by clang from the global defaults,
and remove calls to ClangFilterUnknownCflags.

Squash lists of clang-specific default flags into the main default
flags lists.

Rename Toolchain.Clang*flags to Toolchain.*flags.

Rename Go variables with Clang in the name that have no non-Clang
equivalent.

Remove unused ninja variables.

Bug: 68947919
Test: no change to build.ninja for aosp_cf_x86_64_phone-userdebug or aosp_crosshatch-userdebug
Change-Id: Id287945315d53e5eaef197adbbb4f1302f2e3680
diff --git a/cc/config/arm64_linux_host.go b/cc/config/arm64_linux_host.go
index 83bd799..fa0ee64 100644
--- a/cc/config/arm64_linux_host.go
+++ b/cc/config/arm64_linux_host.go
@@ -15,14 +15,15 @@
 package config
 
 import (
-	"android/soong/android"
 	"strings"
+
+	"android/soong/android"
 )
 
 var (
 	// This is a host toolchain but flags for device toolchain are required
 	// as the flags are actually for Bionic-based builds.
-	linuxCrossCflags = ClangFilterUnknownCflags(append(deviceGlobalCflags,
+	linuxCrossCflags = append(deviceGlobalCflags,
 		// clang by default enables PIC when the clang triple is set to *-android.
 		// See toolchain/llvm-project/clang/lib/Driver/ToolChains/CommonArgs.cpp#920.
 		// However, for this host target, we don't set "-android" to avoid __ANDROID__ macro
@@ -33,9 +34,9 @@
 		// This is normally in ClangExtraTargetCflags, but that's for device and we need
 		// the same for host
 		"-nostdlibinc",
-	))
+	)
 
-	linuxCrossLdflags = ClangFilterUnknownCflags([]string{
+	linuxCrossLdflags = []string{
 		"-Wl,-z,noexecstack",
 		"-Wl,-z,relro",
 		"-Wl,-z,now",
@@ -44,7 +45,7 @@
 		"-Wl,--fatal-warnings",
 		"-Wl,--hash-style=gnu",
 		"-Wl,--no-undefined-version",
-	})
+	}
 
 	// Embed the linker into host bionic binaries. This is needed to support host bionic,
 	// as the linux kernel requires that the ELF interpreter referenced by PT_INTERP be
@@ -73,7 +74,7 @@
 	return "aarch64-linux"
 }
 
-func (toolchainLinuxArm64) ClangCflags() string {
+func (toolchainLinuxArm64) Cflags() string {
 	// The inherited flags + extra flags
 	return "${config.Arm64ClangCflags} ${config.LinuxBionicArm64Cflags}"
 }
@@ -84,7 +85,7 @@
 
 func linuxArm64ToolchainFactory(arch android.Arch) Toolchain {
 	archVariant := "armv8-a" // for host, default to armv8-a
-	toolchainClangCflags := []string{arm64ClangArchVariantCflagsVar[archVariant]}
+	toolchainCflags := []string{arm64ArchVariantCflagsVar[archVariant]}
 
 	// We don't specify CPU architecture for host. Conservatively assume
 	// the host CPU needs the fix
@@ -103,7 +104,7 @@
 		"${config.LinuxBionicArm64Ldflags}",
 		extraLdflags,
 	}, " ")
-	ret.toolchainArm64.toolchainClangCflags = strings.Join(toolchainClangCflags, " ")
+	ret.toolchainArm64.toolchainCflags = strings.Join(toolchainCflags, " ")
 	return &ret
 }