RISC-V support

With some addition to macros the project is able to build on riscv64
machine.

plthook has added RISC-V support upstream [1]. However upstream has
changed their code quite a bit, so I just modified the current vendored
version.

[1]: https://github.com/kubo/plthook/commit/a564738a4707fc5eb4d388b9e97eeab51b8c9d56

renderdoc/3rdparty/plthook/plthook_elf.c

@@ -95,6 +95,9 @@
 #elif defined __powerpc__
 #define R_JUMP_SLOT   R_PPC_JMP_SLOT
 #define Elf_Plt_Rel   Elf_Rela
+#elif defined __riscv
+#define R_JUMP_SLOT   R_RISCV_JUMP_SLOT
+#define Elf_Plt_Rel   Elf_Rela
 #elif 0 /* disabled because not tested */ && (defined __sparcv9 || defined __sparc_v9__)
 #define R_JUMP_SLOT   R_SPARC_JMP_SLOT
 #define Elf_Plt_Rel   Elf_Rela

renderdoc/common/globalconfig.h

@@ -36,8 +36,9 @@
 
 /////////////////////////////////////////////////
 // Build/machine configuration
-#if defined(__LP64__) || defined(_WIN64) || defined(__x86_64__) || defined(_M_X64) || \
-    defined(__ia64) || defined(_M_IA64) || defined(__aarch64__) || defined(__powerpc64__)
+#if defined(__LP64__) || defined(_WIN64) || defined(__x86_64__) || defined(_M_X64) ||        \
+    defined(__ia64) || defined(_M_IA64) || defined(__aarch64__) || defined(__powerpc64__) || \
+    (defined(__riscv64) && __riscv_xlen == 64)
 #define RDOC_X64 OPTION_ON
 #else
 #define RDOC_X64 OPTION_OFF

renderdoc/os/posix/linux/linux_process.cpp

@@ -227,6 +227,15 @@ static uint64_t get_nanotime()
 // the instruction pointer at all.
 #define BREAK_INST_INST_PTR_ADJUST 0
 
+#elif defined(__riscv)
+
+#define INST_PTR_REG pc
+
+// ebreak
+#define BREAK_INST 0x00100073ULL
+#define BREAK_INST_BYTES_SIZE 4
+#define BREAK_INST_INST_PTR_ADJUST 4
+
 #else
 
 #define BREAK_INST 0xccULL