Auto merge of #2700 - kozyilmaz:emptyspaces, r=str4d

PATH variable containing spaces cause build failure

Spaces in PATH variable is creating build issues (observed on macOS). For example "VMware Fusion" adds itself to PATH like `/Applications/VMware Fusion.app/Contents/Public`.

depends/funcs.mk

@@ -129,9 +129,9 @@ $(1)_config_env+=$($(1)_config_env_$(host_arch)_$(host_os)) $($(1)_config_env_$(
 
 $(1)_config_env+=PKG_CONFIG_LIBDIR=$($($(1)_type)_prefix)/lib/pkgconfig
 $(1)_config_env+=PKG_CONFIG_PATH=$($($(1)_type)_prefix)/share/pkgconfig
-$(1)_config_env+=PATH=$(build_prefix)/bin:$(PATH)
-$(1)_build_env+=PATH=$(build_prefix)/bin:$(PATH)
-$(1)_stage_env+=PATH=$(build_prefix)/bin:$(PATH)
+$(1)_config_env+=PATH="$(build_prefix)/bin:$(PATH)"
+$(1)_build_env+=PATH="$(build_prefix)/bin:$(PATH)"
+$(1)_stage_env+=PATH="$(build_prefix)/bin:$(PATH)"
 $(1)_autoconf=./configure --host=$($($(1)_type)_host) --disable-dependency-tracking --prefix=$($($(1)_type)_prefix) $$($(1)_config_opts) CC="$$($(1)_cc)" CXX="$$($(1)_cxx)"
 
 ifneq ($($(1)_nm),)