Fix more aspects of the NaCl build configs.

build/toolchain/nacl/BUILD.gn

Index: build/toolchain/nacl/BUILD.gn
diff --git a/build/toolchain/nacl/BUILD.gn b/build/toolchain/nacl/BUILD.gn
index 1a30bb9a8f88e4d4912dbcdca3da70d19679a65c..1013e1560ad864137c1c6996af90dc454ad897cb 100644
--- a/build/toolchain/nacl/BUILD.gn
+++ b/build/toolchain/nacl/BUILD.gn
@@ -33,6 +33,7 @@ nacl_toolchain("newlib_arm") {
   toolchain_revision = nacl_arm_newlib_rev
   toolchain_cpu = "arm"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/arm-nacl-"
+  is_clang = false
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"
@@ -45,6 +46,7 @@ nacl_toolchain("newlib_x86") {
   toolchain_revision = nacl_x86_newlib_rev
   toolchain_cpu = "x86"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/i686-nacl-"
+  is_clang = false
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"
@@ -57,6 +59,7 @@ nacl_toolchain("newlib_x64") {
   toolchain_revision = nacl_x86_newlib_rev
   toolchain_cpu = "x64"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/x86_64-nacl-"
+  is_clang = false
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"
@@ -89,6 +92,7 @@ nacl_toolchain("glibc_x86") {
   toolchain_revision = nacl_x86_glibc_rev
   toolchain_cpu = "x86"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/i686-nacl-"
+  is_clang = false
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"
@@ -101,6 +105,7 @@ nacl_toolchain("glibc_x64") {
   toolchain_revision = nacl_x86_glibc_rev
   toolchain_cpu = "x64"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/x86_64-nacl-"
+  is_clang = false
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"
@@ -186,6 +191,7 @@ nacl_toolchain("irt_arm") {
   toolchain_revision = nacl_arm_newlib_rev
   toolchain_cpu = "arm"
   toolprefix = "${os_toolchain_dir}/${toolchain_package}/bin/arm-nacl-"
+  is_clang = false
 
   cc = toolprefix + "gcc"
   cxx = toolprefix + "g++"