Land v8-side changes to switch to v8_current_cpu in the GN build.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index d854621a72678ca57d0dd7ba75ee0f3f39f3c9c5..562a5cdc5349fa314bca678af6c8b43c457a8ab5 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -189,7 +189,7 @@ config("toolchain") {
   cflags = []
   ldflags = []
 
-  if (v8_target_cpu == "arm") {
+  if (v8_current_cpu == "arm") {
     defines += [ "V8_TARGET_ARCH_ARM" ]
     if (arm_version == 7) {
       defines += [ "CAN_USE_ARMV7_INSTRUCTIONS" ]
@@ -220,12 +220,12 @@ config("toolchain") {
       }
     }
   }
-  if (v8_target_cpu == "arm64") {
+  if (v8_current_cpu == "arm64") {
     defines += [ "V8_TARGET_ARCH_ARM64" ]
   }
 
   # TODO(jochen): Add support for mips.
-  if (v8_target_cpu == "mipsel") {
+  if (v8_current_cpu == "mipsel") {
     defines += [ "V8_TARGET_ARCH_MIPS" ]
     if (v8_can_use_fpu_instructions) {
       defines += [ "CAN_USE_FPU_INSTRUCTIONS" ]
@@ -260,7 +260,7 @@ config("toolchain") {
   }
 
   # TODO(jochen): Add support for mips64.
-  if (v8_target_cpu == "mips64el") {
+  if (v8_current_cpu == "mips64el") {
     defines += [ "V8_TARGET_ARCH_MIPS64" ]
     if (v8_can_use_fpu_instructions) {
       defines += [ "CAN_USE_FPU_INSTRUCTIONS" ]
@@ -282,23 +282,23 @@ config("toolchain") {
       defines += [ "_MIPS_ARCH_MIPS64R2" ]
     }
   }
-  if (v8_target_cpu == "s390" || v8_target_cpu == "s390x") {
+  if (v8_current_cpu == "s390" || v8_current_cpu == "s390x") {
     defines += [ "V8_TARGET_ARCH_S390" ]
-    if (v8_target_cpu == "s390x") {
+    if (v8_current_cpu == "s390x") {
       defines += [ "V8_TARGET_ARCH_S390X" ]
     }
     if (host_cpu == "x64" || host_cpu == "x86") {
       defines += [ "V8_TARGET_ARCH_S390_LE_SIM" ]
     }
   }
-  if (v8_target_cpu == "x86") {
+  if (v8_current_cpu == "x86") {
     defines += [ "V8_TARGET_ARCH_IA32" ]
     if (is_win) {
       # Ensure no surprising artifacts from 80bit double math with x86.
       cflags += [ "/arch:SSE2" ]
     }
   }
-  if (v8_target_cpu == "x64") {
+  if (v8_current_cpu == "x64") {
     defines += [ "V8_TARGET_ARCH_X64" ]
     if (is_win) {
       # Increase the initial stack size. The default is 1MB, this is 2MB. This
@@ -1587,7 +1587,7 @@ v8_source_set("v8_base") {
     "src/zone.h",
   ]
 
-  if (v8_target_cpu == "x86") {
+  if (v8_current_cpu == "x86") {
     sources += [
       "src/builtins/ia32/builtins-ia32.cc",
       "src/compiler/ia32/code-generator-ia32.cc",
@@ -1625,7 +1625,7 @@ v8_source_set("v8_base") {
       "src/regexp/ia32/regexp-macro-assembler-ia32.cc",
       "src/regexp/ia32/regexp-macro-assembler-ia32.h",
     ]
-  } else if (v8_target_cpu == "x64") {
+  } else if (v8_current_cpu == "x64") {
     sources += [
       "src/builtins/x64/builtins-x64.cc",
       "src/compiler/x64/code-generator-x64.cc",
@@ -1666,7 +1666,7 @@ v8_source_set("v8_base") {
       "src/x64/macro-assembler-x64.cc",
       "src/x64/macro-assembler-x64.h",
     ]
-  } else if (v8_target_cpu == "arm") {
+  } else if (v8_current_cpu == "arm") {
     sources += [
       "src/arm/assembler-arm-inl.h",
       "src/arm/assembler-arm.cc",
@@ -1712,7 +1712,7 @@ v8_source_set("v8_base") {
       "src/regexp/arm/regexp-macro-assembler-arm.cc",
       "src/regexp/arm/regexp-macro-assembler-arm.h",
     ]
-  } else if (v8_target_cpu == "arm64") {
+  } else if (v8_current_cpu == "arm64") {
     sources += [
       "src/arm64/assembler-arm64-inl.h",
       "src/arm64/assembler-arm64.cc",
@@ -1771,7 +1771,7 @@ v8_source_set("v8_base") {
       "src/regexp/arm64/regexp-macro-assembler-arm64.cc",
       "src/regexp/arm64/regexp-macro-assembler-arm64.h",
     ]
-  } else if (v8_target_cpu == "mipsel") {
+  } else if (v8_current_cpu == "mipsel") {
     sources += [
       "src/builtins/mips/builtins-mips.cc",
       "src/compiler/mips/code-generator-mips.cc",
@@ -1813,7 +1813,7 @@ v8_source_set("v8_base") {
       "src/regexp/mips/regexp-macro-assembler-mips.cc",
       "src/regexp/mips/regexp-macro-assembler-mips.h",
     ]
-  } else if (v8_target_cpu == "mips64el") {
+  } else if (v8_current_cpu == "mips64el") {
     sources += [
       "src/builtins/mips64/builtins-mips64.cc",
       "src/compiler/mips64/code-generator-mips64.cc",
@@ -1855,7 +1855,7 @@ v8_source_set("v8_base") {
       "src/regexp/mips64/regexp-macro-assembler-mips64.cc",
       "src/regexp/mips64/regexp-macro-assembler-mips64.h",
     ]
-  } else if (v8_target_cpu == "s390" || v8_target_cpu == "s390x") {
+  } else if (v8_current_cpu == "s390" || v8_current_cpu == "s390x") {
     sources += [
       "src/builtins/s390/builtins-s390.cc",
       "src/compiler/s390/code-generator-s390.cc",