[cscore] Limit jnicvstatic exports to only C and JNI symbols (#2565)

Reduces risk even more about accidentally interfering with OpenCV.

buildSrc/src/main/groovy/SingleNativeBuild.groovy

@@ -79,7 +79,7 @@ class SingleNativeBuild implements Plugin<Project> {
             components.each { component ->
                 if (component.name == "${nativeName}Base") {
                     base = (NativeLibrarySpec) component
-                } else if (component.name == "${nativeName}" || component.name == "${nativeName}JNI") {
+                } else if (component.name == "${nativeName}" || component.name == "${nativeName}JNI" || component.name == "${nativeName}JNICvStatic") {
                     subs << component
                 }
             }

cscore/build.gradle

@@ -18,7 +18,7 @@ apply from: "${rootDir}/shared/jni/setupBuild.gradle"
 model {
     components {
         cscoreJNICvStatic(JniNativeLibrarySpec) {
-            baseName = 'cscore-jnicvstatic'
+            baseName = 'cscorejnicvstatic'
 
             enableCheckTask true
             javaCompileTasks << compileJava
@@ -46,6 +46,13 @@ model {
                 }
                 lib library: "${nativeName}", linkage: 'static'
                 lib project: ':wpiutil', library: 'wpiutil', linkage: 'shared'
+
+                if (it.targetPlatform.operatingSystem.linux) {
+                    it.linker.args '-Wl,--version-script=' + file('src/main/native/LinuxSymbolScript.txt')
+                } else if (it.targetPlatform.operatingSystem.macOsX) {
+                    it.linker.args '-exported_symbols_list'
+                    it.linker.args file('src/main/native/MacSymbolScript.txt').toString()
+                }
             }
         }
     }

cscore/src/main/native/LinuxSymbolScript.txt

@@ -0,0 +1,4 @@
+cscorejnicvstatic {
+  global: CS_*; JNI_*; Java_*; # explicitly list symbols to be exported
+  local: *;         # hide everything else
+};

cscore/src/main/native/MacSymbolScript.txt

@@ -0,0 +1,3 @@
+_CS_*
+_JNI_*
+_Java_*