gollvm: use static linkage for mpc/mpfr/gmp

Pick up static copies of libmpc/libmpfr/libgmp, as opposed to
shared (makes installation logistics easier).

Change-Id: I25b5eb5c3a3e818be3f47fa517ac570906d3316b
Reviewed-on: https://go-review.googlesource.com/114498
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/driver-main/CMakeLists.txt b/driver-main/CMakeLists.txt
index 685b5ac..a3cc685 100644
--- a/driver-main/CMakeLists.txt
+++ b/driver-main/CMakeLists.txt
@@ -39,7 +39,7 @@
 # Add in the libraries for the llvm-goc dependencies.
 target_link_libraries(llvm-goc
   PRIVATE
-  "-L${EXTLIBDIR}" "-lmpc" "-lmpfr" "-lgmp"
+  "-L${EXTLIBDIR}" "-Wl,--push-state" "-Wl,-Bstatic" "-lmpc" "-lmpfr" "-lgmp" "-Wl,--pop-state"
   )
 
 # Create a "compiler built" file each time llvm-goc is built.