Add support for RISC-V

Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>
--- a/webrtc/base/basictypes.h
+++ b/webrtc/base/basictypes.h
@@ -29,6 +29,10 @@
 #define CPU_ARM 1
 #endif
 
+#if defined(__riscv) || defined(_M_RISCV)
+#define CPU_RISCV 1
+#endif
+
 #if defined(CPU_X86) && defined(CPU_ARM)
 #error CPU_X86 and CPU_ARM both defined.
 #endif
--- a/webrtc/typedefs.h
+++ b/webrtc/typedefs.h
@@ -56,6 +56,13 @@
 #elif defined(__powerpc__)
 #define WEBRTC_ARCH_32_BITS
 #define WEBRTC_ARCH_BIG_ENDIAN
+#elif defined(__riscv)
+#if __riscv_xlen == 64
+# define WEBRTC_ARCH_64_BITS
+#else
+# define WEBRTC_ARCH_32_BITS
+#endif
+#define WEBRTC_ARCH_LITTLE_ENDIAN
 #elif defined(__pnacl__)
 #define WEBRTC_ARCH_32_BITS
 #define WEBRTC_ARCH_LITTLE_ENDIAN