RISCV relaxations (#408)

This PR enables RISC-V relaxations and changes to internal linkage for internal function and global symbols.

See also:
https://github.com/llvm/llvm-project/issues/167381#issuecomment-3513830043

Signed-off-by: xermicus <cyrill@parity.io>

crates/integration/codesize.json

@@ -1,10 +1,10 @@
 {
-  "Baseline": 914,
-  "Computation": 2295,
-  "DivisionArithmetics": 14496,
-  "ERC20": 17482,
-  "Events": 1674,
-  "FibonacciIterative": 1490,
-  "Flipper": 2086,
-  "SHA1": 8158
+  "Baseline": 905,
+  "Computation": 2286,
+  "DivisionArithmetics": 14347,
+  "ERC20": 16929,
+  "Events": 1665,
+  "FibonacciIterative": 1447,
+  "Flipper": 2077,
+  "SHA1": 7721
 }