CMakeList.txt: Update code to handle recent changes for `freetype.pc`.

Fixes #1144.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 747fc91..8d6e16a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -498,7 +498,9 @@
 endif ()
 
 
+set(PKGCONFIG_REQUIRES "")
 set(PKGCONFIG_REQUIRES_PRIVATE "")
+set(PKGCONFIG_LIBS "-L\${libdir} -lfreetype")
 set(PKGCONFIG_LIBS_PRIVATE "")
 
 if (ZLIB_FOUND)
@@ -569,10 +571,26 @@
           FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
   string(REPLACE "%ft_version%" "${LIBTOOL_CURRENT}.${LIBTOOL_REVISION}.${LIBTOOL_AGE}"
           FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
-  string(REPLACE "%REQUIRES_PRIVATE%" "${PKGCONFIG_REQUIRES_PRIVATE}"
-          FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
-  string(REPLACE "%LIBS_PRIVATE%" "${PKGCONFIG_LIBS_PRIVATE}"
-          FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+
+  if (BUILD_SHARED_LIBS)
+    string(REPLACE "%PKGCONFIG_REQUIRES%" "${PKGCONFIG_REQUIRES}"
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+    string(REPLACE "%PKGCONFIG_REQUIRES_PRIVATE%" "${PKGCONFIG_REQUIRES_PRIVATE}"
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+    string(REPLACE "%PKGCONFIG_LIBS%" "${PKGCONFIG_LIBS}"
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+    string(REPLACE "%PKGCONFIG_LIBS_PRIVATE%" "${PKGCONFIG_LIBS_PRIVATE}"
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+  else ()
+    string(REPLACE "%PKGCONFIG_REQUIRES%" "${PKGCONFIG_REQUIRES} ${PKGCONFIG_REQUIRES_PRIVATE}"
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+    string(REPLACE "%PKGCONFIG_REQUIRES_PRIVATE%" ""
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+    string(REPLACE "%PKGCONFIG_LIBS%" "${PKGCONFIG_LIBS} ${PKGCONFIG_LIBS_PRIVATE}"
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+    string(REPLACE "%PKGCONFIG_LIBS_PRIVATE%" ""
+            FREETYPE2_PC_IN ${FREETYPE2_PC_IN})
+  endif ()
 
   set(FREETYPE2_PC_IN_NAME "${PROJECT_BINARY_DIR}/freetype2.pc")
   if (EXISTS "${FREETYPE2_PC_IN_NAME}")