libelftc: add RISC-V bfd targets

This adds the following targets: elf32-riscv, elf64-riscv, elf64-riscv-freebsd

Reviewed by:	emaste, markj, jkoshy@users.sourceforge.net
Approved by:	markj (mentor)
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D20768

contrib/elftoolchain/libelftc/elftc_bfd_find_target.3

@@ -76,6 +76,9 @@ Known descriptor names and their properties include:
 .It Li elf32-powerpc Ta ELF Ta MSB Ta 32
 .It Li elf32-powerpc-freebsd Ta ELF Ta MSB Ta 32
 .It Li elf32-powerpcle Ta ELF Ta LSB Ta 32
+.It Li elf32-riscv Ta ELF Ta LSB Ta 32
+.It Li elf64-riscv Ta ELF Ta LSB Ta 64
+.It Li elf64-riscv-freebsd Ta ELF Ta LSB Ta 64
 .It Li elf32-sh Ta ELF Ta MSB Ta 32
 .It Li elf32-shl Ta ELF Ta LSB Ta 32
 .It Li elf32-sh-nbsd Ta ELF Ta MSB Ta 32

contrib/elftoolchain/libelftc/libelftc_bfdtarget.c

@@ -315,6 +315,31 @@ struct _Elftc_Bfd_Target _libelftc_targets[] = {
 		.bt_machine   = EM_PPC64,
 	},
 
+	{
+		.bt_name      = "elf32-riscv",
+		.bt_type      = ETF_ELF,
+		.bt_byteorder = ELFDATA2LSB,
+		.bt_elfclass  = ELFCLASS32,
+		.bt_machine   = EM_RISCV,
+	},
+
+	{
+		.bt_name      = "elf64-riscv",
+		.bt_type      = ETF_ELF,
+		.bt_byteorder = ELFDATA2LSB,
+		.bt_elfclass  = ELFCLASS64,
+		.bt_machine   = EM_RISCV,
+	},
+
+	{
+		.bt_name      = "elf64-riscv-freebsd",
+		.bt_type      = ETF_ELF,
+		.bt_byteorder = ELFDATA2MSB,
+		.bt_elfclass  = ELFCLASS64,
+		.bt_machine   = EM_RISCV,
+		.bt_osabi     = ELFOSABI_FREEBSD,
+	},
+
 	{
 		.bt_name      = "elf64-sh64",
 		.bt_type      = ETF_ELF,