Revert r523218, it breaks build on tier 1

With hat:	portmgr

java/openjdk12/Makefile

@@ -134,9 +134,6 @@ MAKE_ENV+=	USE_CLANG=true
 CONFIGURE_ARGS+=	--disable-warnings-as-errors \
 			--disable-dtrace
 .endif
-.if defined(PPC_ABI) && ${PPC_ABI} == ELFv2
-CONFIGURE_ARGS+=	--disable-precompiled-headers
-.endif
 .if ${ARCH} != amd64
 CONFIGURE_ARGS+=	--enable-aot=no
 .endif

java/openjdk12/files/patch-make_autoconf_flags-cflags.m4

@@ -1,11 +0,0 @@
---- make/autoconf/flags-cflags.m4.orig	2020-01-08 09:12:31 UTC
-+++ make/autoconf/flags-cflags.m4
-@@ -770,6 +770,8 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_CPU_DEP],
-         # for all archs except arm and ppc, prevent gcc to omit frame pointer
-         $1_CFLAGS_CPU_JDK="${$1_CFLAGS_CPU_JDK} -fno-omit-frame-pointer"
-       fi
-+    elif test "x$OPENJDK_TARGET_OS_ENV" = xbsd.freebsd; then
-+        $1_CFLAGS_CPU_JVM="${$1_CFLAGS_CPU_JVM} -DABI_ELFv2 -mcpu=powerpc64 -mtune=power5"
-     fi
- 
-   elif test "x$TOOLCHAIN_TYPE" = xsolstudio; then