RISC-V/testsuite: Add branchless cases for integer cond-move operations

RISC-V/testsuite: Add branchless cases for integer cond-move operations

Verify, for T-Head, Ventana and Zicond targets and the integer
conditional-move operations that already work as expected, if-conversion
to trigger via `noce_try_cmove' at the respective sufficiently high
`-mbranch-cost=' settings that make branchless code sequences produced
by if-conversion cheaper than their original branched equivalents, and
that extraneous instructions such as SNEZ, etc. are not present in
output.  Cover all integer relational operations to make sure no corner
case escapes.

	gcc/testsuite/
	* gcc.target/riscv/movdieq-thead.c: New test.
	* gcc.target/riscv/movdige-ventana.c: New test.
	* gcc.target/riscv/movdige-zicond.c: New test.
	* gcc.target/riscv/movdigeu-ventana.c: New test.
	* gcc.target/riscv/movdigeu-zicond.c: New test.
	* gcc.target/riscv/movdigt-ventana.c: New test.
	* gcc.target/riscv/movdigt-zicond.c: New test.
	* gcc.target/riscv/movdile-ventana.c: New test.
	* gcc.target/riscv/movdile-zicond.c: New test.
	* gcc.target/riscv/movdileu-ventana.c: New test.
	* gcc.target/riscv/movdileu-zicond.c: New test.
	* gcc.target/riscv/movdilt-ventana.c: New test.
	* gcc.target/riscv/movdilt-zicond.c: New test.
	* gcc.target/riscv/movdine-thead.c: New test.
	* gcc.target/riscv/movsieq-thead.c: New test.
	* gcc.target/riscv/movsige-ventana.c: New test.
	* gcc.target/riscv/movsige-zicond.c: New test.
	* gcc.target/riscv/movsigeu-ventana.c: New test.
	* gcc.target/riscv/movsigeu-zicond.c: New test.
	* gcc.target/riscv/movsigt-ventana.c: New test.
	* gcc.target/riscv/movsigt-zicond.c: New test.
	* gcc.target/riscv/movsile-ventana.c: New test.
	* gcc.target/riscv/movsile-zicond.c: New test.
	* gcc.target/riscv/movsileu-ventana.c: New test.
	* gcc.target/riscv/movsileu-zicond.c: New test.
	* gcc.target/riscv/movsilt-ventana.c: New test.
	* gcc.target/riscv/movsilt-zicond.c: New test.
	* gcc.target/riscv/movsine-thead.c: New test.