--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -728,24 +728,18 @@ MOZ_ARG_ENABLE_BOOL(warnings-as-errors,
                           Enable treating warnings as errors],
     MOZ_ENABLE_WARNINGS_AS_ERRORS=1,
     MOZ_ENABLE_WARNINGS_AS_ERRORS=)
 
 dnl ========================================================
 dnl GNU specific defaults
 dnl ========================================================
 if test "$GNU_CC"; then
-    # Per bug 719659 comment 2, some of the headers on ancient build machines
-    # may require gnu89 inline semantics.  But otherwise, we use C99.
-    # But on OS X we just use C99 plus GNU extensions, in order to fix
-    # bug 917526.
+    # We use C99.
     CFLAGS="$CFLAGS -std=gnu99"
-    if test "${OS_ARCH}" != Darwin; then
-        CFLAGS="$CFLAGS -fgnu89-inline"
-    fi
     MKSHLIB='$(CXX) $(CXXFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -Wl,-h,$(DSO_SONAME) -o $@'
     MKCSHLIB='$(CC) $(CFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -Wl,-h,$(DSO_SONAME) -o $@'
     DSO_LDOPTS='-shared'
     if test "$GCC_USE_GNU_LD"; then
         # Some tools like ASan use a runtime library that is only
         # linked against executables, so we must allow undefined
         # symbols for shared objects in some cases.
         if test -z "$MOZ_NO_WLZDEFS"; then

--- a/old-configure.in
+++ b/old-configure.in
@@ -923,24 +923,18 @@ MOZ_ARG_ENABLE_BOOL(warnings-as-errors,
 
 dnl ========================================================
 dnl GNU specific defaults
 dnl ========================================================
 if test "$GNU_CC"; then
     MMX_FLAGS="-mmmx"
     SSE_FLAGS="-msse"
     SSE2_FLAGS="-msse2"
-    # Per bug 719659 comment 2, some of the headers on ancient build machines
-    # may require gnu89 inline semantics.  But otherwise, we use C99.
-    # But on OS X we just use C99 plus GNU extensions, in order to fix
-    # bug 917526.
+    # We use C99.
     CFLAGS="$CFLAGS -std=gnu99"
-    if test "${OS_ARCH}" != Darwin; then
-        CFLAGS="$CFLAGS -fgnu89-inline"
-    fi
     # FIXME: Let us build with strict aliasing. bug 414641.
     CFLAGS="$CFLAGS -fno-strict-aliasing"
     MKSHLIB='$(CXX) $(CXXFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -Wl,-h,$(DSO_SONAME) -o $@'
     MKCSHLIB='$(CC) $(CFLAGS) $(DSO_PIC_CFLAGS) $(DSO_LDOPTS) -Wl,-h,$(DSO_SONAME) -o $@'
     WARNINGS_AS_ERRORS='-Werror'
     DSO_CFLAGS=''
     DSO_PIC_CFLAGS='-fPIC'
     ASFLAGS="$ASFLAGS -fPIC"