Linaro Android toolchain fails to build mpc

[Jim Huang]

After merging commit f0b83e28a379308a3d803c77ec7ad7c10ae12932 (Allow build with prebuilt directory for gmp, mpfr and mpc), Linaro Android toolchain fails to build mpc:

libtool: compile: i686-linux-gnu-gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I/home/jserv/Linaro/android/toolchain/build/temp-src/mpc-0.8.1/src -I.. -I/home/jserv/Linaro/android/toolchain/build/temp-install/include -I/home/jserv/Linaro/android/toolchain/build/temp-install/include -Wall -g -D_REENTRANT -O3 -MT acos.lo -MD -MP -MF .deps/acos.Tpo -c /home/jserv/Linaro/android/toolchain/build/temp-src/mpc-0.8.1/src/acos.c -o acos.o
/home/jserv/Linaro/android/toolchain/build/temp-src/mpc-0.8.1/src/acos.c: In function 'mpc_acos':
/home/jserv/Linaro/android/toolchain/build/temp-src/mpc-0.8.1/src/acos.c:192:19: error: 'GMP_RNDA' undeclared (first use in this function)
/home/jserv/Linaro/android/toolchain/build/temp-src/mpc-0.8.1/src/acos.c:192:19: note: each undeclared identifier is reported only once for each function it appears in
make[3]: *** [acos.lo] Error 1
make[3]: Leaving directory `/home/jserv/Linaro/android/toolchain/build/mpc-0.8.1/src'
make[2]: *** [all-recursive] Error 1

In my Ubuntu environment, libmpc-dev 0.9-1 was installed.

[Jim Huang (jserv)]

Proposed fix:
    https://review.source.android.com/#change,21885