Pass location of built zlib to LLVM cmake.

(cherry picked from commit 56bae3c)

and

(cherry picked from commit 88c338e)

Author: rbvermaa

deps/llvm.mk

@@ -83,7 +83,8 @@ LLVM_CXXFLAGS += $(CXXFLAGS)
 LLVM_CPPFLAGS += $(CPPFLAGS)
 LLVM_LDFLAGS += $(LDFLAGS)
 LLVM_CMAKE += -DLLVM_TARGETS_TO_BUILD:STRING="$(LLVM_TARGETS)" -DCMAKE_BUILD_TYPE="$(LLVM_CMAKE_BUILDTYPE)"
-LLVM_CMAKE += -DLLVM_ENABLE_ZLIB=ON -DLLVM_ENABLE_LIBXML2=OFF -DLLVM_HOST_TRIPLE="$(or $(XC_HOST),$(BUILD_MACHINE))"
+LLVM_CMAKE += -DLLVM_ENABLE_LIBXML2=OFF -DLLVM_HOST_TRIPLE="$(or $(XC_HOST),$(BUILD_MACHINE))"
+LLVM_CMAKE += -DLLVM_ENABLE_ZLIB=ON -DZLIB_LIBRARY="$(build_prefix)/lib"
 LLVM_CMAKE += -DCOMPILER_RT_ENABLE_IOS=OFF -DCOMPILER_RT_ENABLE_WATCHOS=OFF -DCOMPILER_RT_ENABLE_TVOS=OFF
 ifeq ($(USE_POLLY_ACC),1)
 LLVM_CMAKE += -DPOLLY_ENABLE_GPGPU_CODEGEN=ON