--- a/build/autoconf/ffi.m4
+++ b/build/autoconf/ffi.m4
@@ -32,22 +32,16 @@ if test "$MOZ_BUILD_APP" != js -o -n "$J
       ac_configure_args="$ac_configure_args --enable-debug"
     fi
     if test "$DSO_PIC_CFLAGS"; then
       ac_configure_args="$ac_configure_args --with-pic"
     fi
     for var in AS CC CXX CPP LD AR RANLIB STRIP; do
       ac_configure_args="$ac_configure_args $var='`eval echo \\${${var}}`'"
     done
-    old_cflags="$CFLAGS"
-    # The libffi sources (especially the ARM ones) are written expecting gas
-    # syntax, and clang's integrated assembler doesn't handle all of gas syntax.
-    if test -n "$CLANG_CC"; then
-      CFLAGS="-no-integrated-as $CFLAGS"
-    fi
     if test "$CROSS_COMPILE"; then
       export CPPFLAGS CFLAGS LDFLAGS
     fi
     ac_configure_args="$ac_configure_args --build=$build --host=$target"
     if test "$_MSC_VER"; then
       # Use a wrapper script for cl and ml that looks more like gcc.
       # autotools can't quite handle an MSVC build environment yet.
       LDFLAGS=
@@ -78,14 +72,13 @@ if test "$MOZ_BUILD_APP" != js -o -n "$J
 
     # Use a separate cache file for libffi, since it does things differently
     # from our configure.
     old_config_files=$CONFIG_FILES
     unset CONFIG_FILES
     AC_OUTPUT_SUBDIRS(js/src/ctypes/libffi)
     ac_configure_args="$_SUBDIR_CONFIG_ARGS"
     CONFIG_FILES=$old_config_files
-    CFLAGS="$old_cflags"
   fi
 
 fi
 ])
 

--- a/gfx/cairo/libpixman/src/moz.build
+++ b/gfx/cairo/libpixman/src/moz.build
@@ -19,20 +19,16 @@ if CONFIG['OS_ARCH'] != 'Darwin' and CON
             'pixman-arm-neon-asm-bilinear.S',
             'pixman-arm-neon-asm.S',
         ]
     if CONFIG['HAVE_ARM_SIMD']:
         SOURCES += [
             'pixman-arm-simd-asm-scaled.S',
             'pixman-arm-simd-asm.S',
         ]
-    if CONFIG['CLANG_CXX']:
-        ASFLAGS += [
-            '-no-integrated-as',
-        ]
 
 SOURCES += [
     'pixman-access-accessors.c',
     'pixman-access.c',
     'pixman-arm.c',
     'pixman-bits-image.c',
     'pixman-combine-float.c',
     'pixman-combine16.c',

--- a/media/libtheora/moz.build
+++ b/media/libtheora/moz.build
@@ -99,13 +99,8 @@ if CONFIG['GNU_AS']:
         ]]
 
         # These flags are a lie; they're just used to enable the requisite
         # opcodes; actual arch detection is done at runtime.
         ASFLAGS += [
             '-march=armv7-a',
             '-mfpu=neon',
         ]
-
-        if CONFIG['CLANG_CXX']:
-            ASFLAGS += [
-                '-no-integrated-as',
-            ]

--- a/media/libvpx/moz.build
+++ b/media/libvpx/moz.build
@@ -46,20 +46,16 @@ if CONFIG['VPX_ARM_ASM']:
         if f.endswith('.c') and 'neon' in f:
             SOURCES[f].flags += CONFIG['VPX_ASFLAGS']
 
     if CONFIG['OS_TARGET'] == 'Android':
         # For cpu-features.h
         LOCAL_INCLUDES += [
             '%%%s/sources/android/cpufeatures' % CONFIG['ANDROID_NDK'],
         ]
-    if CONFIG['CLANG_CXX']:
-        ASFLAGS += [
-            '-no-integrated-as',
-        ]
 
 # boolhuff_armv5te.asm defines the same functions as boolhuff.c instead of
 # using RTCD, so we have to make sure we only add one of the two.
 if 'vp8/encoder/arm/armv5te/boolhuff_armv5te.asm' not in arm_asm_files:
     SOURCES += [
         'vp8/encoder/boolhuff.c',
     ]
 

--- a/media/openmax_dl/dl/moz.build
+++ b/media/openmax_dl/dl/moz.build
@@ -79,14 +79,8 @@ if CONFIG['CPU_ARCH'] == 'arm' and CONFI
     LOCAL_INCLUDES += [
         '..',
         'api'
     ]
 
     DEFINES['BIG_FFT_TABLE'] = True
 
     FINAL_LIBRARY = 'xul'
-
-    if CONFIG['CLANG_CXX']:
-        ASFLAGS += [
-            '-no-integrated-as',
-        ]
-