Revert accidental commits.

Revert "[RISCV] get toolchain path from enviroment variable"
This reverts commit f9af83f302b397d59361f0dd72f2b55171535901.

Revert "[RISCV] Add a toolchain file for RISC-V."
This reverts commit 8141fe6213d911f469f92bfe5f8a85672f9d8a3d.

Revert "[HACK] Disable matrix_types tests."
This reverts commit a9efc190f2a5c0735562c014211bfce35706d5bd.
diff --git a/SingleSource/UnitTests/matrix-types-spec.cpp b/SingleSource/UnitTests/matrix-types-spec.cpp
index 6e35679..549930d 100644
--- a/SingleSource/UnitTests/matrix-types-spec.cpp
+++ b/SingleSource/UnitTests/matrix-types-spec.cpp
@@ -2,8 +2,7 @@
 // specification.
 
 // Only build the tests if the proper extensions is available.
-// #if __has_extension(matrix_types)
-#if 0
+#if __has_extension(matrix_types)
 
 #include <iostream>
 #include <random>
diff --git a/cmake/caches/target-riscv64-linux.cmake b/cmake/caches/target-riscv64-linux.cmake
deleted file mode 100644
index cdf82c4..0000000
--- a/cmake/caches/target-riscv64-linux.cmake
+++ /dev/null
@@ -1,12 +0,0 @@
-set(CMAKE_SYSTEM_NAME Linux)
-set(triple riscv64-unknown-linux-gnu)
-set(tools $ENV{RISCV_TOOL})
-set(cflags "-mcpu=sifive-u77")
-set(CMAKE_C_COMPILER  ${tools}/bin/clang CACHE STRING "" FORCE)
-set(CMAKE_CXX_COMPILER ${tools}/bin/clang++ CACHE STRING "" FORCE)
-set(CMAKE_C_FLAGS "${cflags}" CACHE STRING "" FORCE)
-set(CMAKE_CXX_FLAGS "${cflags}" CACHE STRING "" FORCE)
-set(CMAKE_C_COMPILER_TARGET ${triple} CACHE STRING "" FORCE)
-set(CMAKE_CXX_COMPILER_TARGET ${triple} CACHE STRING "" FORCE)
-set(CMAKE_C_COMPILER_EXTERNAL_TOOLCHAIN ${tools})
-set(CMAKE_CXX_COMPILER_EXTERNAL_TOOLCHAIN ${tools})