Revert "configure: improve pkg-config support"

This reverts commit 3f8040db.

breaks windows builds

configure

@@ -357,16 +357,6 @@ set_weak(){
     done
 }
 
-set_safe(){
-    var=$1
-    shift
-    eval $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')='$*'
-}
-
-get_safe(){
-    eval echo \$$(echo "$1" | sed 's/[^A-Za-z0-9_]/_/g')
-}
-
 pushvar(){
     for var in $*; do
         eval level=\${${var}_level:=0}
@@ -752,20 +742,6 @@ check_lib2(){
     check_func_headers "$headers" "$funcs" "$@" && add_extralibs "$@"
 }
 
-check_pkg_config(){
-    log check_pkg_config "$@"
-    pkg="$1"
-    headers="$2"
-    funcs="$3"
-    shift 3
-    $pkg_config --exists $pkg || return
-    pkg_cflags=$($pkg_config --cflags $pkg)
-    pkg_libs=$($pkg_config --libs $pkg)
-    check_func_headers "$headers" "$funcs" $pkg_cflags $pkg_libs "$@" &&
-        set_safe ${pkg}_cflags $pkg_cflags   &&
-        set_safe ${pkg}_libs   $pkg_libs
-}
-
 check_exec(){
     check_ld "$@" && { enabled cross_compile || $TMPE >> $logfile 2>&1; }
 }
@@ -847,13 +823,6 @@ require2(){
     check_lib2 "$headers" $func "$@" || die "ERROR: $name not found"
 }
 
-require_pkg_config(){
-    pkg="$1"
-    check_pkg_config "$@" || die "ERROR: $pkg not found"
-    add_cflags    $(get_safe ${pkg}_cflags)
-    add_extralibs $(get_safe ${pkg}_libs)
-}
-
 check_host_cc(){
     log check_host_cc "$@"
     cat > $TMPC
@@ -1180,7 +1149,6 @@ CMDLINE_SET="
     logfile
     malloc_prefix
     nm
-    pkg_config
     samples
     source_path
     strip
@@ -1619,7 +1587,6 @@ host_cc_default="gcc"
 ln_s="ln -sf"
 nm_default="nm"
 objformat="elf"
-pkg_config_default=pkg-config
 ranlib="ranlib"
 strip_default="strip"
 yasmexe="yasm"
@@ -1829,13 +1796,12 @@ set_default arch target_os
 ar_default="${cross_prefix}${ar_default}"
 cc_default="${cross_prefix}${cc_default}"
 nm_default="${cross_prefix}${nm_default}"
-pkg_config_default="${cross_prefix}${pkg_config_default}"
 ranlib="${cross_prefix}${ranlib}"
 strip_default="${cross_prefix}${strip_default}"
 
 sysinclude_default="${sysroot}/usr/include"
 
-set_default cc nm pkg_config strip sysinclude
+set_default cc nm strip sysinclude
 enabled cross_compile || host_cc_default=$cc
 set_default host_cc