Revert "Make cmath patch part of the toolchain (#1149)"

This reverts commit 775ea81181bd15905613f1fd7124d0a1f95a5b69.

build-package.sh

@@ -365,10 +365,10 @@ termux_step_start_build() {
 	# shellcheck source=/dev/null
 	source "$TERMUX_PKG_BUILDER_SCRIPT"
 
-	TERMUX_STANDALONE_TOOLCHAIN="$TERMUX_COMMON_CACHEDIR/${TERMUX_NDK_VERSION}-${TERMUX_ARCH}-${TERMUX_PKG_API_LEVEL}"
+	TERMUX_STANDALONE_TOOLCHAIN="$TERMUX_TOPDIR/_lib/${TERMUX_NDK_VERSION}-${TERMUX_ARCH}-${TERMUX_PKG_API_LEVEL}"
 	# Bump the below version if a change is made in toolchain setup to ensure
 	# that everyone gets an updated toolchain:
-	TERMUX_STANDALONE_TOOLCHAIN+="-v4"
+	TERMUX_STANDALONE_TOOLCHAIN+="-v3"
 
 	if [ -n "${TERMUX_PKG_BLACKLISTED_ARCHES:=""}" ] && [ "$TERMUX_PKG_BLACKLISTED_ARCHES" != "${TERMUX_PKG_BLACKLISTED_ARCHES/$TERMUX_ARCH/}" ]; then
 		echo "Skipping building $TERMUX_PKG_NAME for arch $TERMUX_ARCH"

packages/ndk-stl/build.sh

@@ -8,6 +8,8 @@ termux_step_extract_into_massagedir () {
 	mkdir -p $TERMUX_PKG_MASSAGEDIR/$TERMUX_PREFIX/include/c++/v1/
 	cp -Rf $TERMUX_STANDALONE_TOOLCHAIN/include/c++/4.9.x/* $TERMUX_PKG_MASSAGEDIR/$TERMUX_PREFIX/include/c++/v1/
 
+	( cd  $TERMUX_PKG_MASSAGEDIR/$TERMUX_PREFIX/include/c++/v1/ && patch -p1 < $TERMUX_PKG_BUILDER_DIR/math-header.diff )
+
 	# Revert the patch for <cstddef> that's only used for using g++
 	# from the ndk (https://github.com/android-ndk/ndk/issues/215):
 	cd $TERMUX_PKG_MASSAGEDIR/$TERMUX_PREFIX/include/c++/v1/